It came as_______ surprise that Poland’s President and scores of its top officials were killed in _______ air crash in Russia.
| A．不填; the | B．a; an | C．a; 不填 | D．the; an |
He picked up an envelope________50 dollars in it.
| A．containing | B．contained | C．which contains | D．which was contained |
I didn’t hear the phone. I ________ asleep.
| A．must be | B．must have been | C．should be | D．should have been |
—Does he know how to work out the problem?
—Yes，he has ________ a good idea to solve it.
| A．caught up with | B．kept up with | C．come up with | D．put up with |
The trip will take about five months；it will be a long time ________ we meet them again.
| A．after | B．before | C．since | D．when |
This kind of medicine has a bad ________on our brains.
| A．affection | B．affect | C．effect | D．result |