He looked as if he _____ the answer.
| A．knew | B．had known | C．knows | D．has known |
After the quarrel, I tried all my best to fix the misunderstanding between us, but all my efforts seemed _____.
| A．in trouble | B．in case | C．in effect | D．in vain |
Failure hurts grown-ups and children_____, but it can make a positive contribution to your life once you learn to use it.
| A．actively | B．likely | C．alike | D．similarly |
If the food tastes nice, I’ll go to buy some more; _____, I won’t go.
| A．if not | B．when not | C．if any | D．when ever |
The silence of the library is sometimes broken by a sudden cough or the sound of pages_____.
| A．turning | B．turned | C．being turned | D．having turned |
Not until the train pulled into the next station _____ her suitcase gone.
| A．Mary had found | B．had Mary found |
| C．did Mary find | D．Mary found |