用括号里单词的适当形式填空。

1. —What’s the weather like today?

    —It's        (rain).

2. I walk       (slow) than he.

3. There is a lot of         . It's a       area. (sand)

4. The street is always     _  (crowd), isn't it?

5. If you can't speak English , you can       (simple) speak Chinese in Singapore.

依《合同法》第270条的规定，建设工程合同应采用( )。

A．合同书

B．书面形式

C．数据电文

D．其他形式