21.(2008北京) — Did you return Fred’s call?
— I didn’t need to __________ I’ll see him tomorrow.
A. though B. unless C. when D. because
答案：D
解析：本題考查狀語從句。從句為原因狀語從句，選D，因為我明天就要看見他了，所以沒必要給Fred回電話。

22.(2008北京) I’m sorry you’ve been waiting so long, but it’ll still be some time __________ Brain gets back.
A. before B. since C. till D. after
答案：A
解析：本題考查狀語從句。本題使用了it will be + 一段時間 + before +狀語從句，表示“在……之前還需要一段時間，一段時間之后發(fā)生某事”。后面句子的含義：不過Brain還要過一會兒才能回來。

23.(2008天津) We’ll have a picnic in the park this Sunday __________ it rains or it’s very cold.
A. since B. if C. unless D. until
答案：C
解析：考查狀語從句的引導詞。句意“除非太冷或天太冷，否則我們本周就到公園野餐”，unless引導一個表示否定意義的條件狀語從句。

24.(2008福建) Nancy enjoyed herself so much __________ she visited her friends in Sydney last year.
A. that B. which C. when D. where
答案：C
解析：考查狀語從句。根據(jù)題干意思可知，此處是時間狀語從句，選C。

25.(2008全國I) — Have you got any idea for the summer vacation?
— I don’t mind where we go __________ there’s sun, sea and beach.
A. as if B. as long as C. now that D. in order that
答案：B
解析：as if表示“仿佛，好像”，引導方式狀語從句，now that表示“既然”，引導原因狀語從句；in order that表示“為了”，引導目的狀語從句；as long as表示“只要”，引導條件狀語從句。依句意可知，答話者不介意去任何地方，只要那里有陽光、大海和海灘。

26.(2008山東) He found it increasingly difficult to read, __________ his eyesight was beginning to fail.
A. though B. for C. but D. so
答案：B
解析：考查分句邏輯關系判斷和連詞辨析。由語境可知，后一個分句“視力開始下降”是前一個分句“讀書越來越困難”的原因，所以用for引導原因狀語從句。干擾性最大，但其后要跟結果狀語從句，所以應該排除。Though引導讓步狀語從句，but引導轉(zhuǎn)折關系的分句。

27.(2008遼寧) __________ hungry I am, I never seem to be able to finish off this loaf of bread.
A. Whatever B. Whenever C. Wherever D. However
答案：D
解析：hungry為形容詞，whatever常用來修飾名詞；依句意：無論我多么饑餓，我看起來永遠也不會吃完這塊面包，可知答案為D。

28.(2008遼寧) I used to love that film __________ I was a child, but I don’t feel it that way any more.
A. once B. when C. since D. although
答案：B
解析：once用作連詞，表示“一旦”，引導條件狀語從句；when表示“當……的時候”，常引導時間狀語從句；since表示“從……以來”，引導時間狀語從句，還可以表示“既然”，引導原因狀語從句；although表示“盡管”，引導讓步狀語從句。

29.(2008四川) I haven’t seen Ann for __________ long that I’ve forgotten what she looks like.
A. such B. very C. so D. too
答案：C
解析：此處是“so … that”結構，表示“如此……以至于”。A項用來修飾名詞。

30.(2008四川) There are some chairs left over __________ everyone had sat down.
A. when B. until C. that D. where
答案：A
解析：句意“當大家都就座后還剩下幾把椅子”，此處強調(diào)的是時間。until用于肯定句時一般與連續(xù)性動詞連用，而句子中的sat down是短暫性動詞詞組，因此B項不恰當；C項語法不正確；D項表示地點，不符合題意。

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