第二部分:英语知识运用(共两节,满分 45 分)第一节:单项填空(共 15 小题;每小题 1 分,满分 15 分) 从 A、B、C、D 四个选项中,选出可以填入空白处的最佳选项。21. Great changes ______ in China in the past 20 years.A. took place B. have taken place C. were taken place D. have been taken place
The air in big cities _____very dirty by factories.
The number of people invited _____fifty, but a number of them _____absent for different reasons.
All but one ____here just now.
Father went to his doctor for ____about his heart trouble.
_____turn green in spring.