The dog has a(n) _______ sense of smell while the rabbit has a sharp sense of hearing.
| A．acute | B．cautious |
| C．flexible | D．valid |
When I _________ the past and think how much time has been wasted, my heart bleeds.
| A．look back at | B．look forward to |
| C．look out of | D．look away from |
It was not until his father came back from work _________ the boy began to do his homework.
| A．when | B．which |
| C．that | D．Where |
—When shall we meet again?—Any time that _________ you best.
| A．fits | B．aggress |
| C．matches | D．suits |
—Can Bob help me with this problem?—I’m afraid it's beyond his _________.
| A．strength | B．ability |
| C．energy | D．Force |
I don't like noisy jazz. _________，I enjoy light music, which sounds soft and gentle.
| A．As a result | B．In other words |
| C．In a way | D．On the contrary |