人教版 (新课标)选修7&8选修7Unit 3 Under the sea单元测试一课一练

这是一份人教版 (新课标)选修7&8选修7Unit 3 Under the sea单元测试一课一练，共12页。

选修七 Unit 3《Under the sea》单元测试1

笔试部分：

I. 单项选择
21. — I don't think this TV set is of good quality. Can you replace it with a new one?
— ___________. But I have to talk to my manager first.
A. I'm sorry B. No way C. No problem D. That's a question
22. One of the judges __________ to Gana's film festival was a famous artist from China, Zhang Ziyi.
A. invited B. to invite C. had been invited D. being invited
23. I was scared _______ when I saw the tiger jumped out of the cage and ran to the little child.
A. to the death B. of death C. into the death D. to death
24. Please post this letter in the post office nearby, and __________, I will get two tickets in the train station.
A. in meantime B. on the meanwhile C. in meanwhile D. in the meantime
25. Don't turn the room __________, as I have just tidied it.
A. upside down B. inside C. outside D. inside down
26. Most parents are not __________ the danger of their babies' eating jelly, which causes most unfortunate incidents to happen.
A. well aware to B. very aware of C. aware that D. well aware of
27. Wang Gang is considering buying a computer, is considered to be a great help in our work and study.
A. as B. which C. that D. what
28. As we grow up, it always _______ that after we give something up, we gain something new in its place.
A. suggests B. promises C. requires D. seems
29. The Chinese are proud of the 29th Olympic Games _____ in Beijing in 2008.
A. hold B. being held C. held D. to be held
30. They ______ the _______ snake by using a special kind of powder.
A. poisoned; poisoned B. poisoned; poisonous
C. poisonous; poisoned D. poisonous; poison
31. I need time to _______ on what you offered.
A. consider B. reflect C. imagine D. suggest
32. While shopping, people sometimes can't help ________ into buying something they don't really need.
A. to persuade B. persuading C. being persuaded D. be persuaded
33. Getting a notebook to help you keep a schedule of the things will _______ you putting things off.
A. stop B. keep C. make D. allow
34. Can you imagine a person ___________ in the institutional revolution for doing nothing wrong?
A. putting into prison B. to stay in the prison
C. being put into prison D. to put into prison
35. — I'm dead tired. I can't walk any farther, Jenny.
— _______, Tommy. You can do it!
A. No problem B. No hurry C. Come on D. That's OK

II 完形填空
Many young people in the United States never finish high school. Exactly how many drop out is another issue. Recent studies of 36 rate have had conflicting results.
For one thing, schools define and measure their dropout rates 37 . Some researchers say about 15 to 20 percent of public school students do not 38 their education on time. 39 many other experts and policymakers believe that for the past 20 years, the dropout rate has been around 30 percent. For Latino and black students, the 40 are even larger. Researchers say almost half of them 41 school. At the same time, almost half of the states let students leave school 42 the age of 18 without informing their parents.
Finding a good job 43 a high school education is becoming more and more difficult. A Northeastern University 44 in 2002 found that almost half of all dropouts aged 16 to 24 did not have a job. The 45 of a high school education can also 46 other problems. It is estimated that two-thirds of prisoners in the United States dropped out of high school.
Recent studies have 47 that the majority of students who drop out do it because they are failing. Many are 48 with their classes or feel disconnected from their school and teachers. Some students feel that educators place low 49 on them.
During the past 20 years, there have been efforts to 50 graduation rate through education reforms. Some communities are working on dropout 51 programs. These include some alternative high schools to meet special 52 .
Experts think “early warning systems” can help 53 young schoolchildren at the risk of dropping out of high school. They say schools also need to get 54 more involved, especially if their children are 55 school often.
36. A. research B. finishing C. dropout D. completing
37. A. personally B. individually C. differently D. similarly
38. A. complete B. reach C. practise D. operate
39. A. And B. Besides C. Instead D. But
40. A. people B. students C. dropouts D. numbers
41. A. approach B. leave C. stay D. enter
42. A. after B. until C. before D. when
43. A. without B. together with C. out of D. off
44. A. project B. design C. sketch D. study
45. A. importance B. lack C. need D. requirement
46. A. lead to B. result C. conclude D. include
47. A. noticed B. watched C. shown D. inspected
48. A. bored B. interested C. indifferent D. unconcerned
49. A. outlook B. prediction C. remark D. expectations
50. A. decrease B. reduce C. increase D. unite
51. A. prevention B. conservation C. permission D. admittance
52. A. needs B. ways C. advantages D. means
53. A. receive B. accept C. get D. identify
54. A. mates B. teachers C. parents D. neighbours
55. A. missing B. staying C. leaving D. studying

III 阅读理解
A
For many years, women could only be seen on the seat behind the men operating the two-wheeled motorcycle. Now more and more women are taking the front seat. More than twenty million people in the United States ride motorcycles.
Since 1998 the number of female bikers has risen sharply. Lady Sport Riders began in 1999 in Washington. The women formed the organization to share their love of motorcycle riding. But later it wanted to be more than just an organization for women to gather and ride motorcycles, so it started to organize events that help national health organizations and women's shelters. It also permits women to share a strong sisterhood, and gives financial awards to poor students. Like other motorcycle clubs, the members of Lady Sport Riders also help their community.
Different from male riders, female riders ride for more than fun. This sport gives women a sense of freedom and control. Female riders have helped change motorcycle culture. More than five years ago manufacturers began making equipment especially for women. Some bikes now have smaller, softer seats and controls that are easier to reach. Modern clothes for riding now look good and still provide protection. In the past, women rode motorcycles that traveled at a moderate speed. Now theirs are as powerful as the ones men ride. Safety is very important when riding because the risk of injury is high. So the women wear protective clothing and equipment at all times, especially for the head.
Lady Sport Riders believes women have earned their place in the sport of motorcycle riding. When speaking of male motorcyclists, the members of the club say, “They Made the Game. We Came to Play!”
56. What can we learn from the first paragraph?
A. Motorcycle riding used to be considered a male sport.
B. The number of female motorcyclists is now larger than that of male riders.
C. Female motorcyclists are more skilled at riding than male riders.
D. More and more women have an adventurous spirit.
57. In the beginning, Lady Sport Riders was organized to .
A. allow women to take up motorcycling
B. offer help to national health organizations
C. share their great interest in the sport of motorcycling
D. supply financial help to poor students
58. What do men motorcyclists mainly expect to get from motorcycling?
A. Strength and power. B. A sense of freedom.
C. Money and fame. D. Pleasure from this sport.
59. Compared with the past, the present equipment makes riding more ______ for women.
A. difficult B. pleasant C. risky D. expensive
60. What is the purpose of the passage?
A. To talk about the development of motorcycle riding.
B. To talk about the characteristics of the sport of motorcycling.
C. To introduce a female motorcycle club to readers.
D. To talk about the role women have played in the sport of motorcycling.

B
About 97% of the world's water is salty and is found in our oceans and seas. But, as we can't drink seawater, how can it be important?
Every part of our seas and oceans contains an amazing number of animals and fish that live at different ocean depths. Most of the different species of animals and fish depend on simple plants for their food. These simple plants called algae (海藻) drift near the surface of the ocean and use sunlight to turn carbon dioxide and water into food and oxygen. In fact, algae produce over half of the oxygen people breathe. How important seawater is!
Each plant or animal in our seas and oceans is an important link in a food chain. The algae are eaten in large amounts by microscopic animals, which are in turn consumed by larger animals. These food chains are delicately balanced.
The bad news about the food chains in the oceans is that they are under threat because of man. People once thought that the oceans were so big that it didn't matter if we dumped rubbish into them or caught huge quantities of fish and whales for food. But we now know this is not true and fish stocks in the oceans have started to drop.
Thankfully, the world is taking steps to protect the future of our oceans by introducing international agreements to protect marine habitats. Most countries have introduced fishing restrictions to protect fish stocks in the oceans and new techniques are being pioneered to cope with pollution. Finally, the importance of protecting oceans is being made known to more people. This is just the beginning of a long process to protect the oceans for our future. We depend on the oceans for fish which are an important part of the human diet. How important seawater is!
61. Which of the following is the proper order of the food chain?
A. small animals→algae→microscopic animals→large animals→man
B. algae→microscopic animals→large animals→larger animals→man
C. small animals→algae→large animals→microscopic animals→man
D. microscopic animals→algae→large animals →larger animals→man
62. People used to think that the rubbish thrown into the sea ________.
A. wouldn't harm the fish in the sea B. would change the balance of the food chain
C. would be broken down in the sea D. wouldn't do much harm to the sea
63. From the passage, we learn that _________.
A. most fish and sea animals live at the surface of the seas
B. it is very difficult to break the balance of a food chain
C. excessive fishing has caused the decrease in fish stock
D. it won't be long before the problems concerning oceans will be solved
64. Which of the following is NOT a way being used to protect oceans?
A. The use of international agreements.
B. Forbidding fishing to protect fish stocks.
C. The use of new techniques.
D. Raising people's awareness of the need to protect oceans.
65. What would be the best title of the passage?
A. The importance of seawater.
B. Life in the oceans.
C. How to protect food chains.
D. How to deal with seawater pollution.

C
Homes & Gardens
12mths: £27.04
Established for over 80 years, Homes & Gardens has always been engaging and accessible. Delivering inspirational decorating through real-life stories and beautiful photography, it is the ultimate sourcebook of beautiful ideas and detailed information, and inspires its readers to become their own interior designers.
Delicious
12mths: £29.99
Whether you are passionate about cooking and entertaining, or simply love food, Delicious is the magazine for you. Every month it's packed with mouth-watering recipes, including menus from Jamie Oliver, tasty mid-week suppers and children's meal ideas.
Mother & Baby
12mths: £19.50
Mother & Baby is the UK's best selling parenting magazine, and is full of information on pregnancy, birth and caring for your baby. Mother & Baby has over 40 years of experience on advising mothers how to care for their babies and is a well loved and trusted brand.
TIME
12mths: £34.99
TIME brings you the pick of the most interesting and relevant new stories, delivering accurate knowledge at all times on all topics, which allows you to anticipate trends. With more than 30 million eager readers every week, can you afford not to take TIME?
ON THE WHEEL
12mths: £55.00
The perfect read for anyone interested in classic cars, as it has the best buying advice, road tests and features. Features on restorations, road tests, reader models, keep the car fan entertained every month. The classified section and buyers guide provide a rich source of valuable information on price and makes and models.
66. Those who want to learn about the latest changes in different fields will probably choose _______.
A. Homes & Gardens B. Delicious C. TIME D. ON THE WHEEL
67. Mrs Smith has a baby of only three and she likes to make her home unique, so she may be interested in _______.
A. TIME and Delicious B. Delicious and Mother& Baby
C. TIME and ON THE WHEEL D. Homes & Gardens and Mother & Baby
68. What does Jamie Oliver (mentioned in Delicious) probably do?
A. An engineer. B. A chef. C. An actor. D. A designer.
69. What is the purpose in writing this passage?
A. To talk about the contents of these magazines.
B. To introduce these magazines to readers.
C. To get more readers to subscribe to these magazines.
D. To encourage readers to read as much as possible.
70. The readers of these magazines are possibly _______.
A. men B. women C. children D. grown-ups

D
Now, we know that if we do not get enough vitamins, we are at risk of developing a number of diseases. As a result, vitamin supplements（补品），though expensive, are popular with people who worry that they are not getting enough vitamins from the foods they eat. But contrary to what many people think, medical experts have found little evidence that most supplements do anything to improve health or protect against disease.
In fact, medical experts warn that taking too many of some vitamins can be harmful. For example, too much vitamin E can cause bleeding. People should discuss what vitamins they take with their doctors, as some vitamins can produce harmful side effects when mixed with medicines.
Experts, however, do say that sometimes vitamins can help prevent disease. People who know they lack a particular vitamin should take vitamin supplements. Some older adults, for example, may not have enough vitamin B-twelve. This is because, as people get older, their body loses its ability to take it from foods. Also, people who spend much time inside may need some extra vitamin D as the skin makes this vitamin from sunlight.
Different vitamins are found in different foods. Vitamin A is found in fish liver oil. It also is in the yellow part of eggs. Sweet potatoes, carrots and other darkly colored fruits and vegetables contain substances that the body can change into vitamin A. Vitamin B-twelve is found in green leafy vegetables and other foods, like fruits. Vitamin K can be found in pork products.
In fact, for most people, a balanced diet can ensure enough of the vitamins our bodies need. So, it is important for us to eat a mixture of foods every day to ensure that we get enough vitamins our bodies need.
71. What is probably talked about before this passage?
A. How many vitamins a person's body needs.
B. How many vitamins some foods contain.
C. The benefits that vitamins bring to our health.
D. What people should do to stay healthy.
72. Vitamin supplements are popular with people because ________.
A. people mistakenly think that they are good for their health
B. they contain more vitamins than the foods people eat
C. food does not provide enough vitamins people need
D. people fear that a lack of vitamins will lead to disease
73. From the passage, we can learn that medical experts advise people _________.
A. never to take any vitamin supplements
B. to depend only on food for their vitamins
C. not to take any vitamins together with medicines
D. to consult doctors before taking vitamin supplements
74. For people who lack Vitamin B-twelve, they can eat more from _______.
A. sweet potatoes B. pork products C. green leafy vegetables D. eggs
75. What would be the best title of the passage?
A. Getting enough vitamins through a balanced diet.
B. Vitamin supplements do harm to our health.
C. Vitamins are important to our health.
D. Lacking vitamins can cause many diseases.

IV 阅读表达
阅读下面的短文，并根据文章后的题目要求回答76-80小题。
Most likely, you aren't the family breadwinner. But doing a small job or getting a weekly allowance (零花钱) would put some money in your pocket. For kids and grown-ups alike, money is easy to spend. If you aren't careful, it can be gone in no time.
Being responsible for your money is an important skill to learn — and the sooner you start the better. Whether you are tracking your spending or saving for something special, creating a budget can help you deal with expenses and plan for the future. All you need is paper and a pencil — and some self-control.
First, take a look at our sample monthly budget. Then, use a separate sheet of paper to plan your own. In the first two columns, list your sources of income and how much you expect to earn from them. In the third and fourth columns list what you expect to spend your money on and the amount. The left-hand total should be more than or equal to the right-hand total. If it is, you have an effective budget.
Sample Monthly Budget
Monthly Income
Amount
Monthly Expenses
Amount
Allowance
$ 20.00
Snacks
$ 26.00
Money earned
selling drinks
$ 25.00
Music downloads
$ 12.00
Money earned
babysitting
$ 12.50
Movies
$ 18.00
Money earned
delivering newspapers
$ 30.00
Video records
$ 10.00
Total:
$ 87.50
Total:
$ 66.00
Budgets are not complex, but sticking to them can be tough. When planning your budget, be realistic about your expenses. If you know that you drop $18 at a movie, don't write $12 in that space simply because you wish you were spending less.
If you are eyeing a big purchase, such as a $150 skateboard, spend less and save more until you have the total amount. No matter how attractive it may be, ________________________. One day, you will thank yourself!
76. What is the best title of the passage? (Please answer within 10 words.)
_________________________________________________________________________
77. Which sentence in the passage can be replaced by the following one?
It is important for people to learn to deal with money as early as possible.
___________________________________________________________________________

78. Please fill in the blank in the last paragraph with proper words or phrases to complete the sentence. (Please answer within 10 words.)
_________________________________________________________________________
79. Do you think it is necessary to make a budget? Why? (Please answer within 30 words.)
___________________________________________________________________________

80. Translate the underlined sentence in the fourth paragraph into Chinese.

V 书面表达
随着中国经济的发展，越来越多的人到国外旅游。而其中有些人的不文明行为已经对中国的形象造成了不好的影响。请以“Good Manners Matter”为题写一篇150词左右的短文。
内容要包括：1）你对文明礼仪的看法和认识；2）说出你有怎样的解决方法。
____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________







参考答案
21-25 AADDA 26-30 DBDDB 31-35 BCACC 36-40 CCADD 41-45 BCADB
46-50 ACADC 51-55 AADCA 56-60 ACDBC 61-65 BDCBA 66-70 CDBCD
71-75 CDDCA
阅读表达 (One possible version)
76. How to make a budget.
77. Being responsible for your money is an important skill to learn — and the sooner you start the better.
78. avoid spending your savings
79.（略）
80. 预算并不复杂，但坚持下去很难。
书面表达 (One possible version)
Good Manners Matter
As more and more Chinese go on overseas trips, reports about their bad manners flood in. Many overseas Chinese are embarrassed when foreigners ask them if all Chinese talk loudly and spit everywhere. The poor behavior of some Chinese has done great harm to our reputation for having good manners. China has become an important corner of the global village. We have to understand and respect others' cultures.
We know that it is easier to fall into bad manners than to get into good ones and indeed there are some Chinese people who do have some bad manners, but I firmly believe that we can do something about it. So before you go on your next overseas trip, remember to learn about the culture and people there. Try to say more “Hello” and “Thank you”, and smile to people, even though you don't know them. You will have a better experience and win respect for yourself as well as your country.
重点解析
22. A。invited to Gana's film festival 是过去分词短语作后置定语，修饰the judges。
28. D。依据语境应选seems。it seems that 意为“看起来好像”；而it suggests that意为“它表明 / 暗示”。
30. B。poison 用作动词时，意为“毒死，毒害”；poisonous形容词，意为“有毒的”。
37. C。 后文提到的some researchers和many other experts and policymakers各有不同的看法，所以要用differently。
49. D。place sth on sth意为“以……态度对待”，这句话说明教育者对学生们的期望值较低。
53. D。identify识别，鉴别；这里是说早期发现早期采取措施。
60. C。主旨判断题。文章主要是以Lady Sport Riders为中心，谈论越来越多的女士参加到摩托赛车这项运动中去，只有答案C能体现出整篇文章的关键内容。
62. D。细节推断题。根据第四段中的“People once thought that the oceans were so big that it didn't matter if we dumped rubbish into them …”可知人们过去以为海洋那么大，扔进一点垃圾不会对海洋造成多大的危害。
66. C。细节推断题。答案A、B、D都是针对着某一特殊的领域，Homes & Gardens涉及到家庭装饰，Delicous针对饮食，ON THE WHEEL针对汽车，而只有TIME涉及到各个领域。
71. C。推理判断题。根据文章的第一句话：现在我们可以看出如果体内缺乏维生素，我们就有生病的危险，可以推断前面提到的内容应该是维生素给人体带来的好处。


21. A。考查情景对话。一方说电视机有问题想要换一部，而另一方对这个消息感到抱歉，回答应为I'm sorry。
22. A。invited to Gana's film festival 是过去分词短语作后置定语，修饰the judges。
23. D。短语 (be) scared to death意为“吓死了”。
24. D。in the meantime同时，在此期间。
25. A。upside down 乱七八糟，上下颠倒。
26. D。be well aware of意为“清楚地意识到”。
27. B。本题考查非限制性定语从句。后面的非限制性定语从句来修饰the computer，故用which引导。
28. D。依据语境应选seems。it seems that 意为“看起来好像”；而it suggests that意为“它表明 / 暗示”。
29. D。不定式的被动语态作后置定语。
30. B。poison 用作动词时，意为“毒死，毒害”；poisonous形容词，意为“有毒的”。
31. B。reflect 与on 搭配，意“思考，反思”。
32. C。can't help doing sth 情不自禁做某事。
33. A。stop sb (from) doing sth和keep sb from doing 都意为“阻止某人做某事”，与stop搭配时，from 可以省略，但与keep搭配时from不能省略。如省略，意思就变为“使某人一直做某事”。
34. C。imagine (sb) doing 想像（某人）做某事。
35. C。come on 意为“加油”。
36. C。前后文多次提到dropout“辍学”。
37. C。 后文提到的some researchers和many other experts and policymakers各有不同的看法，所以要用differently。
38. A。根据上下文可以看出这部分学生没有完成学业，故用complete。
39. D。some researchers和many other experts and policymakers各有不同的看法，因此是转折概念，要用but。
40. D。前文的rate和后文的 higher，说明这里谈论的是数字。
41. B。本文主要谈论辍学问题，所以此处应用leave。
42. C。通过the age of 18 without informing their parents可看出，学生是在18岁之前就辍学了。
43. A。becoming more and more difficult说明前文要用without。
44. D。found that是典型的作结论用语，说明前面是一个研究。后文也出现了相同词汇。
45. B。can also说明与前文的类型相同即与without a high school education是同一个概念。所以此处用the lack of a high school education。
46. A。lead to other problems导致其他的问题。
47. C。与前文found that对应。
48. A。failing和后文的 disconnected 说明学生对学习不感兴趣。
49. D。place sth on sth意为“以……态度对待”，这句话说明教育者对学生们的期望值较低。
50. C。efforts和through education reforms说明要增加graduation rates。
51. A。和efforts to increase graduation rates through education reforms有着同样效果的措施就是working on dropout prevention programs，即阻止辍学计划。
52. A。alternative high schools作为解决辍学的一种措施是为满足学生的需要。
53. D。identify识别，鉴别；这里是说早期发现早期采取措施。
54. C。get sb involved意为“让某人关注”，依据上下文应是让孩子的父母关注，故选parents。
55. A。miss school意为“旷课”。
56. A。推理判断题。根据第一段只能判断女摩托车手数量有了很大的增长，但并没有提到在数量或技术上超过了男车手，因此答案B、C错误；文章没有提到女车手数量增加的原因，因此答案D错误；根据文章的第一句话可以判断，摩托赛车曾经是男车手一统天下的运动。
57. C。细节推断题。根据第二段“The women formed the organization to share their love of motorcycle riding.”可知答案。
58. D。细节推断题。根据第三段的首句“Different from male riders, female riders ride for more than fun.”可以看出和男车手不同的是女车手参加这项运动不仅仅是为了娱乐，由此可以判断，男车手参加这项运动的主要目的是为了从运动中获得乐趣。
59. B。根据第三段中的“Some bikes now have smaller, softer seats and controls that are easier to reach. Modern clothes for riding now look good and still provide protection .”这两句话可以看出这些设备的改进都使得这项运动给女士带来更多的方便快乐。
60. C。主旨判断题。文章主要是以Lady Sport Riders为中心，谈论越来越多的女士参加到摩托赛车这项运动中去，只有答案C能体现出整篇文章的关键内容。
61. B。细节推断题。根据第二、三段内容可知答案。
62. D。细节推断题。根据第四段中的“People once thought that the oceans were so big that it didn't matter if we dumped rubbish into them …”可知人们过去以为海洋那么大，扔进一点垃圾不会对海洋造成多大的危害。
63. C。细节推断题。根据第四段中的“… fish stocks in the oceans have started to drop”可知大量捕捉鱼类肯定会造成鱼类储量的下降；根据第二段首句可知答案A错误；根据第三段中的“These food chains are delicately balanced.”可知答案B错误；根据最后一段中的“This is just the beginning of a long process to protect the oceans for our future.”可知答案D错误。
64. B。细节推断题。根据最后一段可知很多国家通过限制捕鱼数量来保护鱼类，但不是禁止捕鱼；其他几种措施在最后一段中都可找到。
65. A。主旨推断题。根据文章的第一段，以及第二段和最后一段的末句可知文章的中心是在说明海水的重要性。
66. C。细节推断题。答案A、B、D都是针对着某一特殊的领域，Homes & Gardens涉及到家庭装饰，Delicous针对着饮食，ON THE WHEEL针对着汽车，而只有TIME涉及到各个领域。
67. D。细节推断题。题目中强调的是Mrs Smith喜欢把自己的家装饰得独特，而且她有个年幼的孩子，所以她可能想了解如何照顾好孩子，因此答案为D。
68. B。推理判断题。Delicious是以饮食为话题的杂志，每期都会有Jamie Oliver提供的菜单，因此他的职业有可能是厨师。
69. C。主旨推断题。文章为广告类，根据文章对于各种杂志内容和特点的介绍，以及所给出的价格，可知其目的是为了让读者订阅。
70. D。推理判断题。从每一种杂志所提供的内容判断，这些杂志都是为成年人出版的。
71. C。推理判断题。根据文章的第一句话：现在我们可以看出如果体内缺乏足够的维生素，我们就有生病的危险，可以推断前面提到的内容应该是足够的维生素会对人体带来的好处。
72. D。细节推断题。根据第一段可知有些人认为自己缺乏维生素，而缺乏维生素会导致人生病，所以他们想通过补充维生素来保持健康。注意答案C的迷惑性，并不是食物无法提供人们所需的维生素，而是人们担心他们不能从食物中获得足够的数量。
73. D。细节推断题。根据第二段中的“People should discuss what vitamins they take with their doctors, …”可知答案。
74. C。细节推断题。根据倒数第二段可知答案。
75. A。主旨推断题。根据文章的最后一段可知：吃维生素补品其实并不像人们想象的那样会带来多大的好处，有时维生素过量会对人体有害，人们通过合理的饮食就能够获得人体所需的维生素。