“直线l垂直于△ABC的边AB，AC”是“直线l垂直于△ABC的边BC”的（　　）

A．充要条件

B．充分非必要条件

C．必要非充分条件

D．即非充分也非必要条件

根据句意及首字母提示，补全单词

1.  Here is no big mall, so the environment is u     __, clean and quiet.

2. You should tell the children not to play in the street, for it's not s          for them.

3. When I need to take some medicine, I could go to d_       to buy some.

4. I have moved into a new house, so I want to have a look in the f___ _ store.

5. Take the e__ __ to the second floor and you'll find the bookstore.