________ doing his experiment, he forgot to pick up his wife from the station.
| A．Absorbed in | B．Absorbed to | C．Absorbing in | D．Absorbing to |
If I ________ your advice then, I think that the crops could be growing better.
| A．took | B．would have taken |
| C．had taken | D．have taken |
If you ________ home without a word, your parents wouldn't be so worried now.
| A．didn't leave | B．couldn't have left |
| C．hadn't left | D．shouldn't leave |
We ________ here on time but we were caught in a traffic jam.
| A．must have arrived | B．could have arrived |
| C．need have arrived | D．should have arrived |
—Can you keep a secret?
—You ________ worry—I'm not going to mention it to anyone.
| A．needn't | B．couldn't |
| C．mustn't | D．won't |
For those of you who ________ a few very popular articles that came out last week, check out this mail.
| A．may miss | B．must have missed |
| C．may have missed | D．would have missed |