My father and my mother have been married for 30 years, and never once ______ with each other.

A. they have quarrelledB. did they quarrel

C. had they quarrelledD. have they quarrelled

Although the old man was ______ death, he still fought with the disease bravely.  　

A. at the end of　B. on the top of 

C. at the edge of　D. on condition that

Many countries are increasing their use of natural gas, wind and other forms of ______.

A. energy     B. power  C. force  D. strength

It may not be a great suggestion. But before ______ is put forward, we will make do with it..

A. a best one   B. the best one   C. a better one  D. a good one

Try not to cough more than you can ______ since it may cause problems to your lungs.

A. help     B. stop     C. allow   D. check

He was unhappy when he sold his guitar. After all, he ______ it for a long time..

A. had had   B. has had    C. has  D. had

Animals are obviously ______ lower form of life than ______ man.

A. the;the     B.a;/    C. a;the      D. /;/

Experts believe ______ people can waste less food by shopping only when it is necessary.  

A. why       B. what   C. where   D. that

My uncle hasn’t been able to quit smoking, but at least he has _______.

A. cut out    B. cut up  C. cut down  D. cut off

______ in the early 20th century, the school keeps on inspiring children’s love of art.

A. FoundedB. To foundC. FoundingD. Having founded