【正文】 d it for three hours he realized it.A. when B. after C. until D. before7) we had seen all the animals, we went home.A. Then B. After C. Though D. While8) She has made many friends she came to our school.A. before B. after C. since D. until9) — How long has the weather been like this?A. Until last night B. Ever since last nightC. Two days ago D. Two days later10) My uncle went to Australia last year. We haven39。t seen him .A. since almost a year B. from almost a year onC. after almost a year D. since almost a year ago11) He was so tired that he fell asleep he went to bed.A. as if B. even though C. ever since D. as soon as12) I knew nothing about the accident my friend told me yesterday.A. because B. since C. until D. after13) I didn39。t manage to do it you had explained how.A. until B. since C. while D. after【Keys】1) C 2) A 3) B 4) B 5) A 6) D 7)B 8) C 9) B 10) D 11) D 12) C 13) A第二節(jié) 條件狀語從句1． 條件狀語從句用一般現(xiàn)在時表示將來。引導(dǎo)條件狀語從句的連詞有： if 如果；unless除非，如果不；on condition that條件是；as long as只要 2．表示正面的條件用if“如果”。 If you don39。t look after young trees, they will die very quickly. If the museum charges for entry, a lot of people won39。t be able to visit it. 3．表示否定的條件用unless( =if.．．not)“除非，如果不”。 I shall not go to the cinema unless I finish my homework before eight. 說明：if…not?？梢杂胾nless替代。 If you don’t study hard, you will fail in the exam. You will fail in the exam unless you study hard.4．表示使某事成為現(xiàn)實必要的條件用on condition that“條件是”，as long as ‘‘只要”。 You may go swimming on condition that you don39。t swim too far away from the river bank. As long as you don39。t study hard, you will fail in the exam.5．祈使結(jié)構(gòu)表條件。 前半部分的祈使結(jié)構(gòu)相當(dāng)于if條件句，可用動詞或名詞開頭；后半部分的簡單句常用一般將來時，有時也用一般現(xiàn)在時。此句型與條件狀語從句形成同義結(jié)構(gòu)。1) 祈使句( , ) +and/then+簡單句 ＝ if 從句(否定式)+主句 Give me somewhere to stand, and I will move the earth.（如果）給我一個支點，我便能掀動地球。 =If you give me somewhere to stand, I will move the earth. One more word, and I39。ll turn you out. 你再多說一句，我就把你趕出去。 =If you speak one more word, I will turn you out. Use your head, then you39。ll find a way. 動動腦子你就能找到辦法。 =If you use your head, you39。ll find a way.2) 祈使句（,）+or+簡單句 ＝ if 從句(否定式)+主語 Work even harder, or you will never pass the exam. 如果不加倍努力，你就永遠無法通過考試。 = If you don39。t work harder, you will never pass the exam.Stop telling lies, or you will be punished. 如果你繼續(xù)說謊，就會受到懲罰。 = If you don39。t stop telling lies, you will be punished.選擇最佳答案填空1) — Would you like to go to the park with me, Susan?— I39。d like to, you don39。t want to go alone.A. until B. before C. if D. after2) Tomorrow we39。ll go to the city park it is sunny.A. as soon as B. when C. if D. as3) All of us will be happy you can e with us.A. while B. if C. but D. or4) Nobody can learn English well you work hard on it.A. if B. unless C. when D. but5) The sports meet will continue it rains this afternoon.A. if B. since C. as soon as D. unless【Keys】1) C 2) C 3) B 4) B 5) D第三節(jié) 原因狀語從句和地點狀語從句1． 原因狀語從句 引導(dǎo)原因狀語從句的連詞有： because, for, since, as, now that 1) because意為“因為”，表示直接的原因或理由，著重點在從句，用于回答why，語氣最強。He is absent today because he is ill. 他今天缺席，因為他病了。I didn39。t go out because I was busy with homework. 我沒有出去，因為我忙于家庭作業(yè)。有時，可用because of后接名詞或代詞表示原因，此時because of=for(介詞)。We won39。t be able to e because of the weather. 由于天氣的原因，我們來不了。She was looking all the better for her stay in hospital. 她因為待在醫(yī)院，顯得好多了。2) for意為“因為”，引導(dǎo)的從句并不說明主句行為發(fā)生的直接原因，只提供補充說明，且不可位于主句前。for前往往用逗號或分號與主句分開，引起的從句對主句加以解釋。I didn39。t go to see him, for a heavy snow