Scientists have to work hard to keep _____ with modern discoveries and developments.
| A．company | B．track | C．touch | D．pace |
-Did you visit the museum last week?
-No, we __________，but we spent too much time shopping.
| A．could have |
| B．could |
| C．must have |
| D．must |
-I can't believe that Jeff __________ have quarreled and fought with his boss.
-Well, if one __________ ask for trouble, it just can't be helped.
| A．would; will |
| B．must; may |
| C．should; must |
| D．need; dare |
I __________ the poor rabbit, but I didn't have the right drugs with me at that moment.
| A．saved |
| B．had saved |
| C．could save |
| D．could have saved |
-Why didn't you buy the gold ring?
-I __________，but I didn't have the money.
| A．would have |
| B．bought |
| C．would like to |
| D．had bought |
-That must have been a long trip.
-Yeah, it __________ us a whole week to get there.
| A．takes |
| B．has taken |
| C．took |
| D．was taking |