Only when class began _______that he had left his book at home.
| A．will he realize | B．he did realize |
| C．did he realize | D．should he realize |
The background music in an assembly line is designed ______.
| A．being not listened to | B．not being listened to |
| C．to be not listened to | D．not to be listened to |
Information and opinion gap exercises have to have some content ______ talking about.
| A．worth while | B．worthily | C．worth | D．worthy |
We know our friends by their defects ______ by their merits.
| A．than | B．in the place of | C．rather than | D．instead of |
Those bad conditions have given ______ to a lot of crime in the area.
| A．reason | B．suspicion | C．rise | D．impulse |
The shoemaker can mend whatever ______.
| A．which needs mending | B．needs to be mended |
| C．it needs mending | D．that needs mending |