— Do you know when he ________ the trip to the USA?

— Perhaps next week, but I’m not sure.

A．makes

B．made

C．has made

D．is making

高层建筑采暖管道安装工艺流程为：安装准备→预制加工→卡架安装→干管安装→立管安装→支管安装→采暖器具安装→（）→调试。

A.冲洗→防腐→试压→保温

B.试压→防腐→保温→冲洗

C.试压→冲洗→防腐→保温

D.冲洗→试压→保温→防腐