第一部分英语知识运用(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.Using _____ illegal drugs can lead to health problems, and it can be _____ stain on one’s life.
A. 不填；the B. the; the C. the; a D. 不填； a
The school shop, customers are mainly students, is closed for the holidays.
| A．which | B．whose | C．when | D．where |
A bank is the place ____they lend you an umbrella in fair weather and ask for it back when it begins to rain .
| A．when | B．that | C．where | D．there |
English is a language shared by several diverse cultures ,each of____ uses it somewhat differently .
| A．which | B．what | C．them | D．those |
The old town has narrow streets and small houses _____are built close to each other.
| A．they | B．where | C．what | D．that |
She showed the visitors around the museum, the construction _____had taken more than three years.
| A．for which | B．with which | C．of which | D．to which |