7.－Who are the teenagers gathering at the school gate?

－Well, if you _____ know, they are all my visiting students.

A. shall　B. can　C. may　D. must

6. When _____, the new school buildings can hold as many as 10,000 students.

A. being completed　B. completed　C. to be completed　D. is completed

5. It was not until he got home _____ Mr. Brown realized he had left his keys in his office.

A. that　B. when　C. where　D. before

4. A Chinese satellite is expected to orbit Mars in 2009, _____ an agreement the country signed with Russia on Monday.

A. instead of　B. in spite of　C. as a result　D. thanks to

3.－It is a long time _____ I saw you last.

－Yes. And it will be a time _____ we see each other again.

A. when; before　B. after; when　C. since; before　D. before; since

2. It’s important for us to use a word or phrase according to the _____ in language studies.

A. situation　B. translation　C. expression　D. condition

1. _____ his arrival at the airport, he was arrested by _____ police.

A. By; the　B. In; a　C. On; the　D. With; 不填