二、单项填空（本节有10小题，每小题1分，共10分）
21. Many people agree that ______ knowledge of English is a must in ______ international trade today.
| A．a; 不填 | B．the; an | C．the; the | D．不填; the |
With the good care taken by doctors and nurses, many patients are beginning to _________.
| A．pick out | B．turn up | C．turn out | D．pick up |
--- I have got a headache.
---No wonder you _________ in front of that computer too long.
| A．work | B．are working | C．have been working | D．worked |
Water can absorb and give off a lot of heat without big changes in temperature, thus creating a ______ environment.
| A．peaceful | B．sensitive | C．common | D．stable |
--- If you like, I can do some shopping for you.
--- That’s a very kind ________.
| A．offer | B．service | C．point | D．suggestion |
Of all the books on the desk, ______ is of any use for study.
| A．nothing | B．no one | C．neither | D．none |