初中英语Unit 7 The unknown world教学课件ppt

这是一份初中英语Unit 7 The unknown world教学课件ppt，共16页。PPT课件主要包含了语法聚焦，课堂练习，原因状语从句，Because，Since，Because of，for，because，because of，Suddenly 等内容，欢迎下载使用。
1. 定义： 在句中用来说明主句原因的句子叫原因状语从句。2. 常用引导词: because(因为)，since(既然)，as(由于)，fr(因为)3. 时态： 原因状语从句一般都是根据实际情况选用适当的时态，通常是主过从过、主现从现。
4. because, since, as和fr的区别： (1)because引导的原因状语从句一般放在主句的后面。当它位于句首时要用逗号与主句分开，放在句中时可不用逗号分开。because表示直接原因，语气最强，适用于回答why引导的疑问句。注意：because和s不可同时出现在一个句子里。如：
We went by bus because it was cheaper.=It was cheaper s we went by bus. 我们乘公共汽车去，因为这样便宜一些。—Why dn’t yu g ut t play ftball with us? 你为什么不和我们一起去外面踢足球？—Because I have t lk after my yunger sister at hme. 因为我得在家照顾我的妹妹。
(2)since引导的原因状语从句一般放在主句之前，表示已知的、显然的理由(通常被翻译成 “既然”，相当于nw that)，较为正式，语气比because弱。如：Since yu dn’t trust him, yu shuld nt emply him. 既然你不信任他，你就不该雇用他。Nw that yu have grwn up, yu shuld nt rely n yur parents. 既然你长大了，就不该依靠你的父母。
(3)as 引导原因状语从句时，表示附带说明的双方已知的原因，含有对比说明的意味，语气比since弱，较为正式，位置较为灵活(常放在主句之前)。如：As it is raining, yu’d better take a taxi. 由于正在下雨，你最好乘坐出租车。I went t bed early, as I was exhausted. 我睡得早，因为我筋疲力尽了。
(4)fr引导的是并列句，表示上文未交代过的原因，但并不说明主句行为发生的直接原因，只提供一些附加或推断的理由。fr引导的并列句只能放在主句之后，并且必须用逗号将其与主句隔开。如：He culd nt have seen me, fr I was nt there. 他不可能见过我，因为我不在那里。He seldm ges ut nw, fr he is very ld. 他现在很少出门了，因为他年事已高。
5. because和because f 的区别：(1)because是连词，其后接原因状语从句或回答以why开头的特殊疑问句。(2)because f是复合介词，其后接名词、代词或动名词。如：He didn’t cme because he was ill.=He didn’t cme because f his illness. 他因病没来。
一、选用because，because f，since，as，fr 填空1. —Why is he unhappy? —____________ he failed the English exam. 2. ____________ everyne is here, let’s begin ur discussin. 3. ____________ the bad weather, the Greens had t put ff their travel plan.
4. We shuld be mre careful, ________ it is already dark. 5. ________ it was a public hliday, all the shps were shut. 6. He sld his car ________ it was t small. 7. ________ yu wn’t help me, I must d the jb by myself. 8. He had a traffic accident __________ his carelessness. 9. This is ________ the Earth is travelling arund the Sun. 10. ________ Jim was nt ready, we went withut him.
二、选择填空( )1. —Why were yu late fr schl again? (原创题)—_____ I gt up late and missed the first schl bus. A. Since B. Because C. AsD. Because f( )2. All f us had t stay at hme _____the COVID-19 during last Spring Festival. (原创题) A. because f B. as C. frD. since
( )3. —_____yu are free tday, why nt see a mvie with me? (原创题)—Sunds great! A. Since B. Fr C. AsD. Because f( )4. —_____it is raining, let’s take a taxi t schl. (原创题)—OK！A. Because B. Fr C. AsD. Because f
( )5. Miss Li must be in the ffice nw,_____ the lights in her ffice are n. (原创题)A. because B. fr C. asD. since
三、语法填空We were n ur way back t the Earth frm anther planet. 1. _____________(sudden), a UFO appeared and it made ur spaceship land n anther planet. On the planet, a very strange-lking alien 2. _______ (meet) us. He tk my friends and 3. ______(my) t see his master. Then we came t a very strange rm. There 4. _________(be) many aliens standing in line. All the aliens had fur eyes, tw heads and six legs. They had a