根据句意及首字母的提示，补全单词。

1.  The old man is not as a_____ as he was.

2.  He headed t    ___the station, he would leave for Shanghai.

3.  I looked down the hall b_____, and there was nobody in it.

4.  Its price has r_____ greatly, so I can't afford it.

5.  He's my friend. we shall not let such a small matter d      __us.

下列化学反应只属于氧化反应，但不属于化合反应的是（  ）

A．二氧化碳溶于水

B．红磷在空气中燃烧

C．木炭在氧气中燃烧

D．石蜡在空气中被点燃