二：语法和词汇知识（共20小题，每小题1分，满分20分）。
6._________we must keep in mind is that we must protect water and use it wisely.
| A．Why | B．What | C．Where | D．How |
________ the little boy looked after his sick uncle a whole year moved us all.
| A．What | B．That | C．When | D．Which |
The food tastes _____ and sells _____.
| A．well; well | B．good; good | C．good; well | D．well; good |
Children in China today have nothing ______.
| A．to worry | B．worried | C．to worry about | D．worrying about |
He must have attended the meeting yesterday,___________ he?
| A．didn't | B．mustn't | C．needn't | D．hasn't |
—Are you worried about her safety?
—Just_______. She isn’t alone.
| A．entirely | B．gradually | C．generally | D．slightly |