—There's someone knocking on the door．Who it be?
—It must be Mary．She promised to be here at 8：00．
| A．must | B．can | C．shall | D．need |
The teacher asked the two students to discuss the question in a low voice______ they should bother the others.
| A．so that | B．in case | C．in order that | D．now that |
One third of the country_____ covered with trees and the majority of the citizens______ black people.
| A．is; are | B．is; is | C．are; are | D．are; is |
Steve Jobs’ death _______ quickly and soon became the talk of the whole world.
| A．expressed | B．spread | C．performed | D．whispered |
It is the prevention of disease_____ its successful treatment that has led to the rapid increase of the world’s population.
| A．more than | B．rather than | C．other than | D．less than |
_______ his grades with Arnold’s, George was quite satisfied.
| A．Compared | B．To compare | C．Comparing | D．Compare |