The teacher suggested that her students__________experiences with ESP.

A．write a composition on their

B．to write composition about the

C．wrote some compositions of his or her

D．had written any compositions for his

加热器都设有危急疏水口，危急疏水分别直接流入（）。

A.除氧器；

B.凝汽器；

C.扩容器；

D.排污器。