根据句意，用括号内所给单词的适当形式填空。

1. It is often ______ (cloud) in Sichuan.

2. I like _____ (make) snowmen very much.

3. He loves going _____ (swim) in summer.

4.The _____ (five) program(节目) is from Ellen and Mary.

5. _____ (not climb) the tree. It's dangerous.

SO₃气浓的两个影响因素分别是（）和工艺风量。

A.原料量

B.硫磺量

C.冷却风量

D.熔硫槽内硫磺液位