We should make a contribution to ________ our country stronger and safe.

A. do B. to do C. doing D. did

A. how many students are there in the classroom

B. how many student were there in the classroom

C. how many students there are in the classroom

D. how many student there had been in the classroom

A. However B. Whenever C. Whatever D. Wherever

A. ears B. arms C. legs D. eyes

A. to　　　　B. for　　　　　 C. that　　　 D. because

A. need to be watered.　　　　 B. have been watered

C. are watering　　　　　　 D. need watered

A. a long time B. for a long time

C. in a long time D. since a long time

A. rain B. raining

C. having rained D. rains

A. with B. by C. on D. at

A. So it was B. So was it C. So it is D. It was so