David’s effort was ______, because he won the first prize in the English speech contest, which made his classmates surprised.
| A．paid off | B．paid back | C．paid for | D．paid up |
I don’t believe you can do today’s job with yesterday’s methods and be in business tomorrow，?
| A．do I | B．don’t I | C．can you | D．can’t you |
Overuse of computers largelyto the failure of his eyesight，which is also a warning message for us all．
| A．contributes | B．turns | C．devotes | D．adjusted |
Seeing a large crowd at the street corner，I became aware ofunusual happening．
| A．anything | B．something | C．everything | D．nothing |
It’s reported that over 70 different emoticons are used in text messages，happy：)is the most popular．
| A．to which | B．that | C．of which | D．which |
The operation I hadjust two months ago and now I have fully recovered．
| A．taken place | B．took place | C．to take place | D．taking place |