1. You will want two trees about ten feet apart, from ________to suspend your tent.

A there

B then

C which

D where That was so serious a matter that I had no choice but ______the police.

A called in

B calling in

C call in

D to call in Americans eat ________as they actually need every day.

A twice as much protein

B protein twice as much

C twice protein as much

D protein as twice much

参考答案：

1. 正确答案：C

例题解析： 介词 关系代词 不定式作定语，只有which 是关系代词。 正确答案：D

例题解析：Have no choice but 后要带接to 的不定式，意思是 只能……别无选择。 正确答案：A

例题解析：译文：美洲人每天所食用的蛋白质是他们实际需要的两倍。倍数 as 形容词 as，表示倍数。