I just don’t understand ______ that leads to so many teenagers becoming addicted to playing computer games.
| A．why it does | B．what it does | C．what it is | D．why it is |
— I hear Jane was knocked down by an electric bicycle and sent to hospital.
— _______, we should go and see her immediately.
| A．If so | B．If necessary |
| C．On condition that | D．Believe it or not |
The books by Mo Yan are so popular that they are in great _______.
| A．quantity | B．progress | C．production | D．demand |
Little _______he was saving every penny he earned in order to go to a fashion school.
| A．the parents did know | B．did the parents know |
| C．knew the parents | D．the parents knew |
The Shopping Festival in China falls on Nov. 11 _______millions of Chinese shoppers go to Tmall.com and Taobao.com.
| A．when | B．that | C．which | D．where |
If I had been a little more careful, I _______the wallet behind.
| A．won't leave | B．hadn't left | C．didn't leave | D．wouldn't have left |