高中英语北师大版 (2019)选择性必修 第一册Lesson 1 The Sixth Extinction导学案及答案

这是一份高中英语北师大版 (2019)选择性必修 第一册Lesson 1 The Sixth Extinction导学案及答案，共19页。
PartⅡ　Lesson 1　The Sixth Extinction

【学习目标】

话题语境
人与自然之人与环境、人与植物的探讨
课时词汇
mass, varied, decrease, blame, rate, quantity
常用短语
die out, be at risk, be to blame, depend on/upon, take action, take steps, set up, in short, wipe out
重点句式
(1)介词提到关系代词前的定语从句
(2)it 作形式主语，主语从句作真正的主语
(3)含有without的含蓄虚拟条件句



单词巧练　写准记牢
Ⅰ.核心单词练习：请根据所给的词性和词义写出单词
1．________________ vt. (使)恢复
2．________________ vi. &vt. (使)孵化
3．________________ adj. 濒危的
4．________________ vt. 影响
5．________________ vt. 责怪，指责
6．________________ vi. &vt. 减少
　　　　　　　n. 减少；减少的量
7．________________ adj. 各种各样的，形形色色的
8．________________ adj. 大量的
9．________________ adj. 异常的；不平常的
10．________________ n. 物种，种

Ⅱ.常用单词练习：根据句意和所给的首字母或中文提示写出符合句中单词的正确形式
1．These exercises will help you ________ (恢复) your full health.
2．Ten chicks ________ (孵化) out this morning.
3．Many measures have been taken to save ________ (濒危的) wildlife in China.
4．So far, more than seven million people ________ (影响) by drought.
5．Which driver was ________ (责怪) for the accident?
6．People should d________ the amount of fat they eat.
7．It is essential that your diet is v________ and balanced.
8．The sky was full of dark m________ of clouds.
9．The weather is a bit u________ these days. It's too hot.
10．There are several thousands ________ of trees here.

Ⅲ.阅读本部分内容，翻译相关短语
1．采取措施 ________________
2．由于，幸亏 ________________
3．总之 ________________
4．处境危险，受到威胁 ________________
5．依赖，依靠 ________________
6．由于 ________________
7．负有责任 ________________
8．毁灭；抹去 ________________
9．消失；绝迹，灭绝 ________________



►第一版块：重点单词
1.mass adj.大批的，数量极多的，广泛的。仅用于名词前。　n．[C]堆，团，块；[C，usually sing.]大量，许多；[pl.]大量的东西　n．[U](物理学中的)质量　the masses [pl.]群众
(教材P52)About what percent of all species on Earth became extinct during the mass extinction known as the “Great Dying”？在被称为“大灭绝”的大规模灭绝期间，地球上的所有物种中，有大约百分之几的物种灭绝了？
mass production 批量生产
a mass of 一堆……；大量的……
masses of 成堆的……；大量的……
a land mass 陆块，地块
❶Their latest product is aimed at the mass market.
他们的最新产品瞄准了大众市场。
❷A mass of books and papers are on his desk.
在他书桌上有一堆书和文件。
❸Wherever the band went，masses of fans would welcome them at the airport.
无论这支乐队去哪儿，都会有大量的歌迷在机场欢迎他们。
❹A liter of gasoline has less mass than a liter of water.
一升汽油的质量比一升水的质量小。
❺The TV programme brings science to the masses and enjoys great popularity.
这个电视节目向群众普及了科学知识，很受欢迎。
特别提醒：
a mass of/masses of后可跟可数名词复数或不可数名词，当“a mass of/masses of＋名词”作主语时，其谓语动词的形式以of后名词所表达的意义而定。
Masses of customers are entering the supermarket.大批顾客正进入超市。
A mass of snow lies in the yard.院子里积了大量的雪。
[即学即练]　判断下列句子中mass的词性及含义/语法填空
①The polar bear is found in the Arctic Circle and some big land masses as far south as Newfoundland.________________
②Recent development has made possible machines that print, cook, and serve foods on a mass scale.________________
③Pluto (冥王星) and Triton (海王卫一) have nearly the same size, mass, and density (密度)．________________
④The government cares much about the interests and well-being of the masses.________________
⑤A mass of work ________ (do) to prevent the river from being polluted up to now.
⑥The young dancers looked so charming in their beautiful clothes that we took ________ (mass) of pictures of them.


2.decrease n．[C，U]减少，降低　vi. & vt.(使大小、数量等)减少，减小，降低
(教材P52)According to scientists，they include volcanic eruptions，asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming.科学家认为原因包括火山爆发、小行星从太空撞击地球、海平面变化、海洋含氧量下降和全球变暖。
a decrease in... 在……方面减少
on the decrease 在减少
decrease by... 减少了……(表示减少的量)
decrease (from...) to... (从……)减少到……(表示减少后的量)
decrease in... 在……方面减少
❶There has been a decrease in the number of young people out of work.
失业青年人数已经有所下降。
❷The demand for corn is on the decrease each year in this country.
这个国家对玉米的需求量在逐年减少。
❸People planted trees on the waste hills to decrease soil erosion.
人们在荒丘上种植树木以减少水土流失。
❹The number of the students in our school has decreased to 1,200.
我们学校的学生数量已减少到1 200人。
❺Compared with last year, the price of wheat has decreased by 15% this year.
和去年相比，今年小麦的价格已降低了15%。
归纳拓展：
increase
(1)vi. &vt. (使)增长，增多，增加
(2)n.[C，U]增长，增多，增加
increase to... 增加到……(表示增加后的量)
increase by... 增加了……(表示增加的量)
on the increase 在增加
increase in... 在……方面增加

表“开、关”的英语短语
比较：
①the door/window
②turn on/off the light/the radio
③switch on/off the electric machine
注意：旋转开关的电器用turn on/off
闸刀开关的电器用switch on/off
门窗用open/close
[即学即练]　单句语法填空
①In recent years some Inuit people in Nunavut have reported increases ________ bear sightings around human settlements, leading to a belief that populations are increasing.
②The accidents have decreased ________ 20% since the measures were taken.
③The crime rate in this area has decreased ________ the lowest level nowadays.
④Tea is still a large part of daily life in the UK today, but it seems to be ________ the decrease.
⑤Food prices increased ________ 10% in less than a year.


3.blame vt.责怪，指责，把……归咎于　n．[U]责任，责备
(教材P52)This time, human activity will be to blame.这次，人类活动是肇因。
blame...for (doing) sth. 因(做)某事责备……
blame sth. on sb./sth. 把某事归咎于某人/某事
be to blame for (doing) sth. 因(做)某事应受责备；对(做)某事负有责任(不定式用主动形式表示被动意义)
take/bear the blame for sth. 承担某事的责任
lay/put the blame (for sth.)on... 把(某事的)责任归咎于……
❶Don't blame him for breaking that vase; after all, he is only a child.
别怪他打碎了那个花瓶，毕竟，他只是个孩子。
❷They blamed the failure of the business on the economic downturn.
他们把生意的失败归咎于经济衰退。
❸The hot weather is partly to blame for the water shortage.
炎热的天气是缺水的部分原因。
❹We were ready to take the blame for what had happened.
我们准备好对所发生的事承担责任。
❺Health officials put the blame for the disease on poor housing conditions.
卫生官员们将该疾病的暴发归咎于恶劣的居住条件。
语境串记：
He is blamed for the big mistake, but he blamed it on others. In fact, it is he, not others, that is to blame for it.他因这次严重的错误受到了责备，但他把它归咎于别人。事实上，应该是他，而不是别人，应对此负责。
考向追踪：
高考通常从以下几个角度设题对blame进行考查；
(1)to blame作表语或定语时要用主动形式表示被动意义；(2)通过非谓语动词结构对blame进行考查；(3)blame后的介词既可以用on又可以用for，on表示责怪的对象，for表示责怪的原因。
[即学即练]　单句语法填空/单句写作
①Some people blame the smartphone ________ the tragedy, yet in fact people's weakening self-control and self-discipline are ________ (blame)．
②Lots of people find it hard to get up in the morning, and put the blame ________the alarm clock.
③不要总是把自己的失败归咎于他人。你自己应该对其负责。
________________________________________________________________________
④科学家认为该疾病的暴发应归咎于被污染的水。
________________________________________________________________________


4.varied adj.各种各样的，形形色色的
(教材P52)The reasons for extinctions are varied.物种灭绝的原因多种多样。
vary v. 存在不同之处；使多样化
vary from... to... 在……到……的范围内变化
various adj. 各种各样的
variety n. 品种；种类；多样化；变种
a variety of sth. 各种各样的某事/物
❶Anything will become boring if you do it repeatedly. The key is to develop a balanced and varied programme that is fun as well as progressive.如果你重复做一件事，任何事情都会变得无聊。关键是要制订一个既有趣又能取得进步的平衡而又丰富多样的计划。
❷The number of the added flights varies from year to year according to the demand shown by flight ticket booking systems.根据机票预订系统显示的需求，新增航班的数量每年都在变化。
❸Skilled workers also combine various hardwoods and metal to create special designs.
熟练的工人还将各种硬木和金属结合起来，创造出特殊的设计。
❹Join us to taste a variety of fresh local food and drinks.
加入我们，与我们一起品尝各种新鲜的本地食物和饮料。
词语比较：
various, different, varied, variable
(1)different adj.“不同的”，可以和单数或复数名词连用。
如：This is a totally different matter.这完全是另外一回事儿。
The two boys told one and the same story in different words.这两个孩子说的故事是一样的，只是用词不同。
(2)various adj.各种各样的。指同一范畴内的不同种类。后面只用复数名词。如：
Representatives from various parts of the country have arrived in Beijing.全国各地的代表到达北京。
(3)variable易变的。如：
He is of a variable mood; he never finishes what he starts.他是个易变脾气的人/没有准脾气的人，从来不做完已经开始的事情。
(4)varied adj.种种的；各种各样的，富有变化的
a varied life丰富多彩的生活
varied types of happiness各种各样的幸福
[即学即练]　单句语法填空/单句写作
①The quality of their products never ________ (vary); it is always excellent.
②These opinions change with time, and vary ________ place to place.
③The supermarket offers ________ (vary) goods to choose from, so more and more people prefer to shop there.
④人们对这部新剧发表了各种各样的意见。(varied)
________________________________________________________________________
⑤大学所学的课程往往与当今工作所需要的各种知识和技能不相匹配。(varied)
________________________________________________________________________




5.rate n．[C]速度；比率；价格，费用　vt.&vi.评价，评估；vt.划分等级
(教材P52)Although it is not unusual for species to die out naturally, the rate at which this is now happening is cause for concern.虽然物种的自然灭绝并不罕见，但现在灭绝发生的速度让人担忧。
at a(n)．..rate 以……速度
one's heart rate 某人的心率
interest rate 利率
birth/death rate 出生率/死亡率
high success/failure rate 很高的成功率/失败率
❶Babies do not grow at a steady rate but in stops and starts.
婴儿成长的速度并非一成不变，而是长长停停，停停长长。
❷The new technique has a high success/failure rate.
这种新技术的成功率/失败率很高。
❸How do you rate him as a football player?
你怎么评价他作为一个足球运动员的表现？
❹She is currently rated number two in the world.
她目前排名世界第二。
构词法：
后缀-rate表示“程度；水平(与first、second等词连用，表明你认为某物属于哪种程度或水平)”。
The school has educated many first-rate students.这所学校培养出很多一流的学生。

归纳拓展：
rating n．[C]等级，级别
credit rating (银行等作出的)信用等级评定
(2)与rate相关的常见短语：
at any rate (强调事情的真实性)无论如何，不管怎样
at this/that rate 照此情形，如此下去
I may be away on business next week but at any rate I'll be back by Friday.我下周可能要出差，但无论如何，我最晚星期五回来。
At this rate, we won't get home until midnight.照这样下去，我们得半夜才能到家。
[即学即练]　判断下列句子中rate的词性及含义/单句语法填空
①Hospital patients who see tree branches out their window are likely to recover at a faster rate than patients who see buildings or sky instead.________________
②The exchange rate is in our favour for the time being.________________
③This year, our school has been rated as one of the most excellent schools in the local area.________________
④The golf is rated among the top ten sports in that country.________________
⑤The new car has been given an excellent safety ________ (rate)．
⑥________ this rate, this species of animal could become extinct in less than 10 years.

6.quantity n．[C，U]数量，数额，数目；大量；[U]量
(教材P55)He went to a city where iron was produced in huge quantities.他去了一个大批量生产铁的城市。


❶We consumed vast quantities of food and drink that night.
那天晚上我们大吃大喝了一顿。
❷A large quantity of books are stored in the library near the playground.
大量的书被保存在操场附近的图书馆里。
❸Large quantities of water are needed to water the fields in this area.
这个地区需要大量的水来灌溉田地。
❹They are now developing ways to produce the vaccine cheaply in large quantities.
目前他们正在研究大批量廉价生产这种疫苗的方法。
quantity和quantities前面可以用large, vast, huge等词修饰。
特别提醒：
“a quantity of＋不可数名词”作主语时，谓语动词用单数形式；“a quantity of＋可数名词复数”作主语时，谓语动词用复数形式；”quantities of＋可数名词复数/不可数名词”作主语时，谓语动词用复数形式。
A large quantity of soil is washed away by rain every year.每年都有大量的土壤被雨水冲走。
Large quantities of money have been spent on bringing up the three children.抚养这三个孩子已经花费了许多钱。
[即学即练]　单句语法填空/完成句子
①In the picture we can see that there ________ quantities of apples in the basket and there ________ a large quantity of milk in the bucket. (be)
②若是你大量订购的话，我认为有可能会打折。
If you order it ________________________， I think a discount will be possible.


►第二版块：重点短语
1.die out 灭绝，消失
(教材P52)How many times up to today has life on Earth almost died out？到今天为止，地球上出现过几次生物几乎灭绝的情况？
die off 相继死去
die from/of 死于
be dying for sth. 渴望某物，极想要某物
be dying to do sth. 渴望做某事
die down (to become gradually less strong, loud, noticeable, etc.)
逐渐变弱，逐渐平息
die away (to become gradually weaker or fainter and finally disappear)
逐渐减弱，逐渐消失
❶This species has nearly died out because its habitat is being destroyed.
因栖息地正受到破坏，这一物种已濒临灭绝。
❷That style of music died out hundreds of years ago.
那种风格的音乐几百年前就消失了。
❸When the applause had died down, she began her speech.
掌声平息后她便开始演讲了。
❹The sound of his footsteps died away.
他的脚步声渐渐消失了。
易混比较：
die away与die out, die down
(1)die out通常指物种灭绝或习俗消失
(2)die away(指运行中的车的声音)逐渐减弱(到消失)
(3)die down(指风势或火势)逐渐变弱
(4)die off相继死去
如：①The sounds of the train died away.火车的声音渐渐消失。
②The fire/wind gradually died down.(火/风势逐渐减弱)
③The animals in the forest died off.森林里的动物相继死去。
④Dinosaurs died out a very long time ago.恐龙很久以前就灭绝了。
[即学即练]　用die的相关短语完成句子
①With more and more birds ______________， some day some species will ______________. In addition, some of them have ________________ environmental pollution.
②Don't worry. The strong wind will ________________ soon and we can go out to have a baseball match as planned.
③Now I'm thirsty and ________________ a glass of water. I have walked for a long time.


2.wipe out 彻底消灭，全部摧毁　使(人)疲惫不堪
unusual adj.不寻常的，罕见的；独特的，与众不同的
(教材P52)Extinctions, where entire species are wiped out, are not unusual in our Earth's history.物种灭绝，即整个物种的完全消失，在地球的历史上并不罕见。
It is unusual for sb. to do sth.　　　做某事对某人来说是不寻常的。
❶A volcanic eruption nearly wiped out the small island in 1997.
1997年的一次火山喷发差点把这个小岛毁灭了。
❷Nothing could wipe out his bitter memories of the past.
什么也抹不掉他对过去的痛苦记忆。
❸All that travelling has wiped her out.一路舟车劳顿让她疲惫不堪。
❹It's not unusual for him to feel very angry in a situation like this.
在像这样的情况下他觉得非常生气并不罕见。
❺He was an unusual man with great business talents.
他是一个与众不同的人，很有商业天赋。
联想串记：
usual adj.寻常的，惯常的
as usual 像往常一样，照例
unusual adj. 不寻常的；独特的
unusually adv. 不寻常地；特别地
usually adv. 通常地，一般地
构词法：
“un-”是常见的否定前缀，常可加在形容词前表示相反的状态。常见的词有：unknown(未知的)，unsafe(不安全的)，unpleasant(令人不快的)等。
语境串记：
It is unusual that the rain suddenly falls today, but he still goes running in the park as usual. He usually says, “Once you have got into the habit of exercising, you will stick to it.”不寻常的是，今天突然下起雨来，但是他仍然像往常一样在公园里跑步。他经常说，“你一旦养成了锻炼的习惯，就会把它坚持下去。”
[即学即练]　单句写作/单句语法填空
①地震把这个小村庄彻底毁灭了。
________________________________________________________________________
②史密斯照例是第一个到达教室的。
________________________________________________________________________
③在英国找到一个这么大的湖泊是不寻常的。
________________________________________________________________________
④Fear and hate for others is ________ (usual) caused by ignorance (无知). We're scared of the things that we don't understand.
⑤This time, we stayed together, in case anything else ________ (usual) happened.


3．at risk 意为“有危险，冒风险”
(教材P53)Of course, as we humans depend on so many species for our survival, we would also be at risk of dying out.当然，由于人类的生存依赖很多种物种，我们也会有灭绝的危险。
at the risk of doing sth. 冒着做某事的风险
take a risk/risks (to do sth.) 冒险(做某事)
run the risk (of sth./of doing sth.) 冒……的风险；冒险(做某事)
run risks 冒险
risk doing sth. 冒险做某事
Cloning may greatly contribute to human medicine, but we must use it cautiously, because it may put people at risk.克隆可能会对人类医学有很大帮助，但是我们必须谨慎地利用它，因为它可能会给人们带来危险。
联想串记：


[即学即练]　结合risk的用法完成句子
①He got well prepared for the job interview, for he couldn't ________________________ (冒险失去这次良好的机会)．
②If you ________________________ (冒险不系安全带), you will be ________________ (处于危险中)．
③In spite of great danger, the soldier jumped into the river and ________________________ (冒着生命危险救那个女孩)．
④Though it is fun to play on the frozen river, ________________________ (这有危险)．


►第三版块：典型句式
1.reason后接定语从句的用法
(教材P53)There is a long list of reasons why so many species are dying out: air and water pollution, forests being destroyed, factory farming and overfishing.导致这么多物种正在消亡的原因有很多：空气和水污染、森林被毁、工厂化养殖和过度捕捞。
reason作先行词，后接定语从句时：
(1)若关系词在从句中作状语，要用why或for which引导定语从句。
(2)若关系词在从句中作主语、宾语，要用which或that引导定语从句，其中作宾语时关系词可省略。
❶There's a reason why/for which people don't read this stuff: it's not funny.
人们不读这种东西是有原因的：它并不逗趣。
❷The reason why/for which he was late was that he got up late.他迟到的原因是他起床晚了。
❸He gave us a reason that/which sounded reasonable.
他给了我们一个理由，这个理由听起来合情合理。(关系词在从句中作主语)
❹The reason (which/that) he has given sounds reasonable.
他给出的理由听起来合情合理。(关系词在从句中作宾语，可省略)
归纳拓展：
a/the reason for (doing) sth. (做)某事的原因
a/the reason to do sth. 做某事的原因
a/the reason why/for which...is that... ……的原因是……
[即学即练]　单句语法填空
①The reason ________ I admire him is ________ his positive attitude to life has a great influence on me.
②Is this the reason ________ he explained at the meeting for his carelessness in his work?
③Another reason ________ corn's rise: The government encourages farmers to grow corn instead of rice ________ (improve) water quality.


2.“without＋名词”引导含蓄条件句
(教材P53)Without forests, we would have no air to breathe, and without clean water we would be unable to survive.没有森林，我们就不能呼吸空气；没有干净的水，我们将无法生存。
虚拟条件句的条件有时不通过条件从句来表示，而是通过介词短语、上下文或其他方式表现出来，这种虚拟条件句叫作含蓄条件句。含蓄条件句的具体用法如下：

❶They wouldn't have reached the agreement so easily without that common ground.
没有共同的立场，他们是不会那么容易达成协议的。
❷But for your help, we couldn't have succeeded.
要不是你帮忙，我们不可能成功。
❸I got up very early yesterday morning, or I could not have caught the early bus.
昨天早上我起床很早，否则就赶不上早班车了。
❹I was too busy at that time. Otherwise, I would have called you.
我那时太忙了，否则我就给你打电话了。
介词without的用法
(1)without是with的反义词，意为“不”或“没有”。
We can do the work without your help.我们可以没有你的帮助而做这项工作。
They worked the whole day without taking any rest.他们工作了一整天而未休息。
(2)without可用在双重否定句中，往往是用介词短语代替整句。
No man gets into the condition you are in without the aid of his own folly.＝No man gets into the condiction you are in if he has not his own folly to blame.如果不是由于自己的愚蠢，没有人会落到你现在所处的这般光景。
(3)without是介词，不是连接词，后面只能接名词或动名词，不能接不定式。
(4)without常可用来表示条件。如：
We could never have succeeded in what we were doing without his guidance.如果没有他的指导，我们的工作决不会成功。
句中without his guidance＝if we hadn't had his guidance.
[即学即练]　单句语法填空/完成句子
①Without his support, we wouldn't ________ (be) where we are now.
②—Do you have Betty's phone number?
—Yes. Otherwise, I wouldn't ________ (be) able to reach her yesterday.
③飞机晚点一个多小时才起飞，否则我就不会让你等这么久了。
There was a delay of over an hour before the plane took off; otherwise I ________ (keep) you waiting for such a long time.



3.“介词＋关系代词”引导定语从句
(教材P53)Although it is not unusual for species to die out naturally, the rate at which this is now happening is cause for concern.
尽管物种自然灭绝并不罕见，但它目前的发生速度令人担忧。
(1)引导定语从句的关系代词不仅可以作动词的宾语，还可以作介词的宾语。若将介词提至关系代词之前，便形成了“介词＋关系代词”结构，该结构可引导限制性或非限制性定语从句；此结构中的关系代词可为which(先行词指物)，whom(先行词指人)。
(2)“介词＋关系代词”结构中介词的确定
在“介词＋which(先行词是物)/whom(先行词是人)/whose(所有格，既可指人又可指物)”引导的定语从句中，介词的选用有以下三种方式：
①根据定语从句中谓语动词或形容词的搭配确定
②根据与先行词的搭配确定
③根据主从句的逻辑关系而定(通常是with/without)
❶The official to whom we applied for a permit was very kind.
给我们申请许可证的那位官员非常友好。
❷Have you found the book on which I spent ￡10?
你找到那本我花了10英镑买的书了吗？
❸He was the man by whomMasteroftheGame was translated.
他就是翻译《谋略大师》的那个人。(be translated by)
❹The two things of which they felt proud were Jim's gold watch and Della's hair.
他们感到骄傲的两样东西是吉姆的金表和德拉的头发。 (be proud of)
❺I will never forget the day on which I first met him.
我永远也忘不了第一次见他的那一天。(on the day)
❻Rose helped me a lot, without whose help I would not have passed the exam.
罗丝帮助了我很多，没有她的帮助我不会通过考试。
特别注意：
listen to, look at, look for, depend on, pay attention to, take care of等固定短语中的介词一般不放在关系代词前。
This is the girl whom/who/that he will take care of.这就是他将照料的女孩。
“介词＋关系代词”结构
可代替when, where, why, that等关系副词。如：
①There used to be a time at which/during which (＝when) the Chinese people struggled for freedom.
②In 2006, we moved to Boston, in which (＝where) my grandparents lived.
③There's no reason for which (＝why) we shouldn't be friends.
④There are varieties of ways in which (＝that) we can solve the problem.
(注：that在这里用作关系副词)
[即学即练]　单句语法填空
①The fellow, ________ whom I spoke made no answer at first.
②The West Lake, ________ which Hangzhou is famous, is a beautiful place.
③In his room, I saw a big desk ________ which there were all kinds of books.
④Yesterday we had a meeting ________ which we discussed many problems.
⑤Air, ________ which man couldn't live, is really important.
⑥This book has opened a window, ________ which we can see a wonderful world.
⑦Yesterday we paid a visit to the house ________ which Lu Xun once lived.
⑧Who is the person with ________ you shook hands just now?
⑨Mr Li has two sons, both of ________ are college students.


4.it作形式主语
(教材P53)It is clear that human activity has negatively affected all other species on Earth, including animals and plants.很明显，人类活动已经对地球上其他所有物种产生了负面影响，包括动物和植物。
主语从句充当主语时，为使句子平衡，常用it作形式主语，将主语从句后置，主语从句可用that，what，who，whether，why等词引导。常见的此类句式有：
(1)It＋be＋名词＋从句
It＋be＋a pity/shame that... 遗憾的是……
It＋ be＋ no wonder that... 难怪……
It＋be＋no surprise that... ……不足为奇
(2)It＋be＋形容词＋从句
It＋be likely that... 可能……
It＋be clear/obvious that... 显而易见的是……
(3)It＋动词的被动语态＋从句
It＋be said that... 据说……
It＋be reported that... 据报道……
It＋be believed that... 人们相信……
It＋be suggested/ordered/demanded that...(should) do...
建议/命令/要求……(从句要用虚拟语气，即从句谓语动词用should do, should可以省略)
(4)It＋特殊动词＋从句
It occurs to sb. that... 某人突然想到……
It happens that... 碰巧的是……
It doesn't matter＋who/why/what... ……无所谓/没关系
❶It is a pity/shame that you have missed such a wonderful lecture.
你错过了这么精彩的演讲，真遗憾。
❷She is hard-working, so it is no surprise that she has won first prize.
她学习努力，所以她获得一等奖不足为奇。
❸It is obvious that the way coffee is grown affects many aspects of life.
很明显，咖啡的种植方式影响了生活的很多方面。
❹It is said that about 20% of 25-34-year-olds live with their parents, compared with 16% in 1991.据说在25到34岁的人群中大约有20%和父母住在一起，而在1991年这一比例是16%。
❺It is generally believed that a balanced diet is a key to people's health.
人们普遍认为均衡的饮食是健康的关键。
❻It is demanded by my violin teacher that I (should) practise playing the violin every day.
我的小提琴老师要求我每天练习拉琴。
❼It occurred to him that his farm had much potential.他突然想到他的农场还是很有潜力的。
句型It is that...的转换：
(1)It is said that sb. has done sth.
→Sb. is said to have done sth.
据说某人已经做了某事
It is said that sb. is doing sth.
→Sb. is said to be doing sth.
据说某人正在做某事
(2)It is reported that sb. is doing sth.
→Sb. is reported to be doing sth.
据报道某人正在做某事
It is reported that sb. has done sth.
→Sb. is reported to have done sth.
据报道某人已经做了某事
(3)It is believed that sb. is doing sth.
→Sb. is believed to be doing sth.
人们相信某人正在做某事
It is believed that sb. has done sth.
→Sb. is believed to have done sth.
人们相信某人已做了某事
(4)It is known that sb. is doing sth.
→Sb. is known to be doing sth.
众所周知某人正在做某事
It is known that sb. has done sth.
→Sb. is known to have done sth.
众所周知某人已经做过某事了
[即学即练]　单句语法填空/根据括号内提示，用it作形式主语单句写作
①It doesn't matter ________ he says.
②It is not clear ________ will attend to this matter.
③It doesn't interest me ________ or not you succeed.
④很显然，地球是圆的。(obvious)
________________________________________________________________________
⑤我很荣幸被邀请参加你的生日聚会。(an honour)
________________________________________________________________________
⑥许多学生认为英语是一门有趣的学科。(consider)
________________________________________________________________________
⑦他在这次坠机事件中幸免于难真是奇迹。(wonder)
________________________________________________________________________
⑧人们常常建议生病时要多喝水。(suggest)
________________________________________________________________________
⑨我们已经决定将会议推迟到下周一。(decide)
________________________________________________________________________



[词语积累]
①wipe out彻底消灭，全部摧毁
②unusual/ʌn'juːʒuəl/adj.特别的，不寻常的，罕见的
[反义]usual adj.寻常的，通常的
③varied/'veərid/adj. 各种各样的，不相同的；多变的
④volcanic eruption火山喷发
⑤asteroid/'æstərɔɪd/n.[C]小行星
⑥decrease/dɪ'kriːs/n.[C，U]减少，降低，减少量vt.&vi.(使大小、数量等)减少，减小，降低
⑦be to blame (for sth.)(对坏事)负有责任
blame vt.归咎于，责怪，指责
⑧at...rate以……的速度
rate n．[C]速度；比率
⑨cause for concern担忧的原因
⑩based adj.在……居住(或工作)
⑪look at思考，考虑，研究
⑫factory farming工厂化养殖
⑬overfishing/ˌəʊvə'fɪʃɪŋ/
n．[U]过度捕捞
[构词法]over-可用作前缀，表示“太，过于”。
overproduction n．[U]生产过剩
overconfident adj.过分自信的，自负的
⑭affect/ə'fekt/vt.影响
[辨析]effect n．[C，U]效应，影响
⑮survival n．[U]生存，存活
survive vi. 生存，存活
⑯at risk有危险，冒风险
⑰avoid (doing) sth.避免(做)某事
⑱take action采取行动
[近义]take steps/measures采取措施
⑲endangered/ɪn'deɪndʒəd/
adj.(物种)有灭种危险的，濒临灭绝的
⑳solar adj.太阳能的；太阳的
solar energy/power太阳能
in short总之，简言之
[同义]in a word/in brief
lay eggs下蛋，产卵
begin a programme开始一项计划
[拓展]programme构成的常见搭配：develop/set up/launch/carry out a programme拟订/制订/启动/实施计划
raise vt. 饲养，培育
hatch vi.孵化
restore/rɪ'stɔː(r)/vt.使复原
habitat/'hæbɪtæt/n.[C，U](动植物的)生活环境，栖息地
natural habitat天然栖息地
wildlife habitat野生动植物的生存环境

Extinctions, where entire species are wiped out①， are not unusual② in our Earth's history. In fact, over 90 percent of all species that ever lived are now extinct. In the last 500 million years, there have been five times when life on Earth has almost ended. These include the third mass extinction, known as the “Great Dying”， which killed 90% to 96% of all species 【1】. And the fifth event, which occurred 66 million years ago, caused the death of the dinosaurs. The reasons for extinctions are varied③. According to scientists, they include volcanic eruptions④， asteroids⑤ hitting the Earth from space, changes in sea levels, the decrease⑥ of the oxygen content of the sea and global warming. Many scientists say we are now entering the Earth's sixth mass extinction. This time, human activity will be to blame⑦.
【1】画线部分中“known as the ‘Great Dying’”为过去分词短语作后置定语，与which引导的非限制性定语从句共同修饰the third mass extinction。
Although it is not unusual for species to die out naturally, the rate⑧at which this is now happening 【2】 is cause for concern⑨. A 2015 study by scientists who were based⑩ at Brown University and Duke University in the US, looked at⑪ how quickly species die out due to natural causes, that is, the “background extinction rate”. They found that human activity is causing species to die out 1,000 times faster than normal.There is a long list of reasons why so many species are dying out 【3】： air and water pollution, forests being destroyed, factory farming⑫ and overfishing⑬. It is clear that human activity has negatively affected⑭ all other species on Earth, including animals and plants.
【2】画线部分为“介词＋关系代词”引导的定语从句，修饰the rate。介词at的选用是考虑到与rate搭配。
【3】画线部分为why引导的定语从句，修饰reasons, why在从句中作状语。
If a sixth mass extinction occurs, scientists who have studied the issue believe that up to three quarters of all species on Earth could die out 【4】. Of course, as we humans depend on so many species for our survival，⑮ we would also be at risk⑯ of dying out. Our world and our lives depend on the balance in nature between animals and plants. Without forests, we would have no air to breathe, and without clean water we would be unable to survive 【5】．
【4】本句的结构分析如下：
If_a_sixth_mass_extinction_occurs，
If 引导的条件状语从句
主句
【5】该句为含蓄条件句。介词短语Without forests和without clean water相当于条件，“we would have no air to breathe”和“we would be unable to survive”表示与现在事实相反的假设。
Can a sixth extinction be avoided⑰？ Experts say that it is not yet too late, if we take action⑱ now. This would mean we have to significantly change the way we live. For example, we need to take steps to save endangered⑲ species, including setting up special areas where plants and animals can be protected. We need to change how we work and travel by using cleaner, more natural sources of energy, such as wind and solar⑳ energy. We also need to improve our farming methods to reduce water, air and land pollution. In short， if we want to survive, we need to stop destroying the planet that we live on and start to protect it.
Case Study
The Black Robin
Black robins are the birds that humans saved from extinction. In 1980, there were only five black robins left in the world. They all lived on a small island off the coast of New Zealand. Only one of those birds, a female called Old Blue, was able to lay eggs.Wildlife workers began a programme for raising black robin chicks. They protected Old Blue's eggs, helped them to hatch， and took care of the chicks. Thanks to their efforts, there are now more than 250 black robins, and the population is spreading. To help them survive, people are restoring their habitats and removing small animals that hunt them, such as mice and cats from the islands where they live.

物种灭绝，即整个物种的完全消失，在地球的历史上并不罕见。事实上，曾经存在的物种中90%以上现在都已经灭绝。在过去的五亿年中，地球上出现过五次生物几乎全部灭绝的情况。这其中包括称为“大灭绝”的第三次灭绝，那期间90%至96%的物种灭亡了。6 600万年前发生的第五次灭绝导致了恐龙的灭亡。灭绝的原因各不相同。科学家认为原因包括火山爆发、小行星从太空撞击地球、海平面变化、海洋含氧量下降和全球变暖。许多科学家认为地球的第六次大灭绝即将来临。这次，人类活动是肇因。
虽然物种的自然灭绝并不罕见，但现在灭绝发生的速度让人担忧。2015年美国布朗大学和杜克大学的科学家进行的一项研究，调查了物种因自然原因灭亡的速度，即“背景灭绝率”。他们发现人类活动导致物种灭亡的速度比正常情况快1 000倍。导致这么多物种正在消亡的原因有很多：空气和水污染、森林被毁、工厂化养殖和过度捕捞。显然，人类活动对地球上所有其他物种产生了负面影响，包括动物和植物。
研究该问题的科学家们相信，如果发生第六次大灭绝，地球上多达四分之三的物种有可能灭绝。当然，由于人类的生存依赖很多种物种，我们也会有灭绝的危险。我们的世界和我们的生命依赖于动植物之间的自然平衡。没有森林，我们就不能呼吸空气；没有干净的水，我们将无法生存。
第六次灭绝可以避免吗？专家说，如果我们现在采取行动还为时不晚。这意味着我们必须极大地改变生活方式。例如，我们要采取措施拯救濒临灭绝的物种，包括建立动植物的特殊保护区。通过使用更清洁、更自然的能源来改变我们的工作和出行方式，例如风能和太阳能。我们还需要改进耕作方式，减少水、空气和土地污染。简言之，我们如果想要生存，就需要停止破坏我们生活的地球并开始保护它。
案例研究
黑知更鸟
黑知更鸟是人类从灭绝危机中拯救出来的鸟类。1980年，世界上只剩下五只黑知更鸟。它们都栖息在新西兰海岸附近的一个小岛上，其中只有一只名叫“老蓝”的雌鸟能够产卵。野生动物工作者开始了一项黑知更鸟繁育计划。他们保护“老蓝”的蛋，帮助孵化，并照顾幼鸟。多亏他们的努力，现在黑知更鸟已超过250只，而且数量还在增加。为了帮助它们生存，人们正在恢复黑知更鸟的栖息地并迁移捕杀它们的小动物，例如岛上的老鼠和猫。



Ⅰ.单词拼写
1．Held inside for too long, regret can a________ the immune system.
2．A special team was sent there to look into the cause of the train accident, and the investigation suggested that high speed was to b________.
3．In most cases, a healthy diet can help you d________ the risk of getting some diseases like diabetes.
4．Overfishing has resulted in many large sea creatures like whales and sharks becoming ________ (濒危的) species.
5．Nowadays, ________ (大批的) unemployment seems to be a fact of life in this country.
6．These speakers impressed us deeply with their ________(不平常的)confidence and performance.
7．This professor discovered some rare ________ (物种)of plants deep in this forest last summer.
8．Roofs and windows of buildings aren't the only surfaces that can be used to produce ________ (太阳能的)power.
9．Theories about why Stonehenge was put there are ________ (各种各样的). It may be a place for observing the stars and planets.
10．The local organisation has spent millions of dollars in an attempt to ________ (使恢复) the habitat of native plants.

Ⅱ.单句语法填空
1．Over the past several years, the South African penguins have been ________ the decrease in numbers.
2．In fact, when you blame someone ________ what you're going through, you refuse responsibility.
3．It's said that such animals like dinosaurs died ________ because they couldn't adapt to the sudden change in climate.
4．The performance was so good that the applause didn't die ________ until there was an encore (返场加演节目)．
5．In most cases, good communication can help wipe ________ misunderstanding and build a good relationship.
6．As the chart shows, the sales this year decreased ________ 30%.
7．People who sit for a long time were ________ great risk of diseases when compared with those who sit less.
8．We depend on wildlife and on the planet's rich biodiversity for our ________ (survive) and well-being.
9．As we all know, with the development of science and technology, the earth's resources are running out ________ an alarming rate, so we should make good use of them.
10．Great quantities of sand ________ (be) washed down the hillside by the rain last night.
11．Without your help, I would not ________ (win) the first prize in the contest last term.
12．The reason ________ he resigned his post was ________ there was a more attractive and challenging job for him.
13．Biologists warned that changes caused by a warming planet were behind the bears' ________ (usual) behavior and could affect the entire ecosystem.
14．My brother lent me the money, otherwise I couldn't ________ (afford) the trip.
15．But for the soldiers who set up defence against the floods in time, the cities on the lower part would ________ (fall) into a bigger mess.

Ⅲ.用方框内短语的适当形式填空(有两项为多余选项)
at the rish of　at risk　wipe out　die from　be to blame　take steps　die out
1．The patient was still ________________ because after the operation, his body rejected the new heart.
2．In fact, women are less likely to have high blood pressure or ________________ heart attacks.
3．There are still many people suffering a lot, and we are to do something to ________________ poverty.
4．It is you as well as your wife that ________________ for your son's bad performance at school.
5．We should ________________ to keep all these rare animals and plants under good protection.

Ⅳ.课文语法填空
In the last 500 million years, there have been five times when life on Earth has almost ended. The reasons for extinctions are 1.________ (vary). According to scientists, they include volcanic 2.________ (erupt), asteroids hitting the Earth from space, changes in sea levels, the decrease of the oxygen content of the sea and global warming. Many scientists say we are now 3.________ (enter) the Earth's sixth mass extinction. This time, human activity will be 4.________ (blame) .
They found that human activity is causing species to die out 1,000 times 5.________ (fast) than normal. If a sixth mass extinction 6.________ (occur), scientists 7.________ have studied the issue believe that up to three quarters of all species on Earth could die out. We need to take steps to save endangered species, 8.________ (include) setting up special areas where plants and animals can 9.________ (protect). We need to change how we work and travel by using cleaner, more natural sources of energy, such as wind and solar energy. We also need to improve our farming methods to reduce water, air and land pollution. In short, if we want to survive, we need to stop destroying the planet that we live 10.________ and start to protect it.










PartⅡ　Lesson 1　The Sixth Extinction
双基夯实·课前排查
Ⅰ.
1．restore　2.hatch　3.endangered　4.affect　5.blame
6．decrease　7.varied　8.mass　9.unusual　10.species
Ⅱ.
1．restore　2.hatched　3.endangered　4.have been affected
5．to blame　6.decrease　7.varied　8.masses　9.unusual
10．species
Ⅲ.
1．take steps/action　2.thanks to　3.in short　4.be at risk　5.depend on　6.due to　7.be to blame　8.wipe out
9．die out
核心突破·要点讲解
►第一版块：重点单词
1．①n.块　②adj.大批的　③n.质量　④n.群众　⑤has been done　⑥masses
2．①in　②by　③to　④on　⑤by
3．①for　to blame　②on　③Don't always blame your own failure on others. You yourself should take/bear the blame for it.　④The scientist thought that the polluted water was to blame for the illness.
4．①varies　②from　③various/varied　④Varied opinions were expressed about the new play.　⑤The courses studied in universities often do not match the varied knowledge and skills required for work today.
5．①n.速度　②n.价格；费用　③vt.评价，评估　④vt.划分等级　⑤rating　⑥At
6．①are　is　②in quantity或in large quantities
►第二版块：重点短语
1．①dying off; die out; die from/of　②die down/away
③dying for
2．①The small village was wiped out by the earthquake.　
②As usual, Smith was the first one to arrive at the classroom.　③It is unusual to find a lake of this size in Britain.　④usually　⑤unusual
3．①risk losing this good opportunity　②risk not wearing a seat belt; at risk　③risked his life to save the girl/took the risk of losing his life to save the girl　④it is risky
►第三版块：典型句式
1．①why; that　②that/which　③for; to improve
2．①be　②have been　③would/could not have kept
3．①to/with　②for　③on　④at　⑤without　⑥through/from　⑦in　⑧whom　⑨whom
4．①what　②who　③whether　④It is obvious that the earth is round.　⑤It is an honour that I was invited to your birthday party.　⑥It is considered by many students that English is an interesting subject.　⑦It is a wonder that he survived the plane crash.　⑧It is often suggested that one (should) drink plenty of water when he/she is sick.　⑨It is decided that the meeting has been put off until next Monday.
夯实基础·一遍落实
Ⅰ.
1．affect　2.blame　3.decrease　4.endangered　5.mass
6．unusual　7.species　8.solar　9.varied　10.restore
Ⅱ.
1．on　2.for　3.out　4.down　5.out　6.by　7.at
8．survival　9.at　10.were　11.have　won　12.why; that
13．unusual　14.have afforded　15.have fallen
Ⅲ.
1．at risk　2.die from　3.wipe out　4.are to blame
5．take steps
Ⅳ.
1．varied　2.eruptions　3.entering　4.to blame　5.faster　6.occurs　7.who/that　8.including　9.be protected　10.on