---A man is not born in ____ of knowledge.

---True. We all gain our knowledge by keeping on learning in our life

A．exhibition

B．possession

C．civilization

D．protection

在一氧化碳还原氧化铜的实验中，为了防止尾气污染空气，应用（　　）

A．、水吸收尾气

B．、硫酸吸收尾气

C．石灰水吸收尾气

D．酒精灯点燃尾气