Many people agree that______ knowledge of English is a must in______ international trade today.
| A．a; 不填 | B．the; an | C．the; the | D．不填；the |
This is a process happens when land becomes desert people cut down trees and dig up grass.
| A．when; because | B．that; because of | C．when; because of | D．which; because |
The director thought I was referring to her,in fact, I was referring to the men on duty.
| A．when | B．where | C．which | D．while |
With several students , Mr. Smith came into the lab.
| A．follow | B．followed | C．following | D．to follow |
I couldn’t fall asleep. Every night the house as heavy trucks went past.
| A．struck | B．beat | C．hit | D．shook |
While working in the countryside, the students a great deal of knowledge on plant life.
| A．looked up | B．picked up | C．put up | D．called up |