语法练习

1.There is no doubt ___ all the flights have been canceled because of the snowstorm.
A.when
B.that
C.why

D.whether

2.___ has been known for about a hundred years, its commercial development has taken place since the beginning of the century.

A.Which
B.While
C.That

D.As

3.The drill has been designed so ___ through the earth to a depth of 35,000 feet.

A.to bore
B.that it will bore
C.as it bore

D.boring

4.Sharon was supposed to be here at 10 o'clock. She ___ about our meeting.

A.would have forgotten
B.should have forgotten
C.ought to have forgotten

D.must have forgotten

5.This may have preserved the elephant from being wiped out as well as other animals ___ in Africa.

A.hunted
B.hunting
C.that hunted

D.are hunted

答案详解

1.[B]【解析】that从句作名词doubt的同位语。doubt同时在there be结构中作主语。

2.[D]【解析】as引导非限制性定语从句，表达整个主句的意思，as在从句中作主语。

3.[B]【解析】so that...引导目的状语从句，相当于so as to bore或in order to bore。

4.[D]【解析】must have done表示从现在的角度对过去情况进行肯定的推测。

5.[A]【解析】other animals是被猎杀的对象，因此选择被动语态。另外，as well as连接两个对等成分，此处完整结构应为：“the elephant from being wiped out as well as other animals from being hunted in Africa.”from being与前文重复，可以省略。