碳二加氢反应器出口乙炔不合格的原因可能有（）。A．冷箱压力波_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题多项选择题

碳二加氢反应器出口乙炔不合格的原因可能有（）。

A．冷箱压力波动

B．系统负荷波动

C．氢气干燥器切换

D．氢气干燥器备用时未进行实气置换

答案

参考答案：A, B, C, D

完形填空

There are times when people are so tired that they fall asleep almost anywhere. We can see there is a lot of sleeping on the bus or train on the home from work in the evenings. A man will be the newspaper, but seconds later，with his head down, it as if he is trying to it . Or he will fall asleep on the shoulder of the stranger next to him. place where unplanned short sleep is in the lecture hall where a student will start snoring（打鼾）so that the professor has to ask another student to the sleeper awake. A more embarrassing（尴尬）situation happens when a student starts falling into sleep and the of the head pushes the arm down off the , and the movement causes the of the body to move together and finally he falls down to the floor. The student wakes up on the floor with no of the reason for getting there. The worst time to fall asleep is when . Police reports are full of that happen when people fall into sleep and go the road. If the drivers are , they are not seriously hurt. One woman’s car, , went into the river. She woke up in four feet of and thought it was raining. When people are really , nothing will stop them from falling asleep—no matter where they are.

D．for example

单项选择题

动物细胞的细胞周期长短主要是由（）期决定的。

A.G1

B.S

C.G2

D.M期