He went there, ______ some books and call on an old friend of his.

A．bought

B．buying

C．buy

D．to buy

无机酸性腐蚀品()遇有机物稻草易氧化发热而引起燃烧。

（A）甲酸 

（B）硝酸 

（C）冰醋酸 

（D）酚