换热器在投用时引入冷介质的操作中应首先打开冷介质的()。A、入口阀 B、出口阀 C、关闭 发布时间:2018-11-22 08:35 │ 来源:www.tikuol.com 题型:单项选择题 问题: 换热器在投用时引入冷介质的操作中应首先打开冷介质的()。A、入口阀B、出口阀C、关闭副线阀D、放空阀
题型:单项选择题 —Our teacher wouldn't give us the answer to the questions directly.—Why not work them out all by _____?[ ]A. themselves B. himselfC. ourselves D. myself 查看答案