二、单项选择（共15小题，每题1分，满分15分）
21. In recent years ____ global warming is becoming ____ concern for people all over the world.
- the; the B. /; / C. /; a D. the; /
22. The number of people who English as a foreign language more than 750 million.
A .learns; is B. learn; are C. learns; are D. learn; is
23. That hero who died in the war was so brave that he never ___________ to the enemies until death.
A. gave up B. gave in C. gave away D. gave out
24. Barack Obama delivered a speech to 500 local youths during his visit to China, many of ________ were from Fudan University and Tongji University.
A. them B. whom C. which D. those
25．Tell him ＿＿＿＿＿＿＿ his bike when he leaves．
A．not to forget locking B．don’t forget locking
C．not to forget to lock D．don’t forget to lock
