Your donation_________ and the money will be used to help the students from poor families.

A．is greatly appreciating

B．appreciates

C．has appreciated

D．is greatly appreciated

由于（）等原因会产生过烧。

A.炉内气氛氧化性太强

B.钢在高温中停留时间过长

C.加热温度过高

D.炉膛压力过低

E.不完全燃烧