He had to sell his luxury car, ________ his company was in debt.
| A．before | B．until | C．while | D．for |
Controlling water-pollution is necessary_____ it will be expensive.
| A．so that | B．as if | C．even though | D．ever since |
Such a person _____ you talked about is seldom seen now.
| A．that | B．whom | C．who | D．as |
_______ the teacher’s instruction in the lab_____ important.
| A．Following; are | B．Following; is | C．Followed by; are | D．To follow; are |
E-mail, as well as telephones, ______ an important part in daily communication.
| A．is playing | B．have played | C．are playing | D．play |
Professor Wang has written some short stories, but he is______ known for his plays.
| A．the best | B．more | C．better | D．the most |