在锅炉水循环回路中，当受热弱的上升管循环流速等于负值时，称为

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问题填空题

在锅炉水循环回路中，当受热弱的上升管循环流速等于负值时，称为（）。

答案

参考答案：循环倒流

选择题

We hoped that the bird had found some friendly person, landed on his shoulder, ______．

A．expected to love and care for

B．expecting to love and care for

C．expecting to be loved and cared for

D．to expect to be loved and cared for

判断题

对于易燃易爆容器的动火,可以先动火后办证。