适用于介质温度范围在-20～200℃的调节阀上阀盖应选用（）。A、_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

适用于介质温度范围在-20～200℃的调节阀上阀盖应选用（）。

A、普通型

B、散（吸）热型

C、长颈型

D、波纹管密封型

答案

参考答案：A

填空题

根据短文内容，用方框中所给单词的适当形式填空，每词限用一次。

enough call twice special way

We all need to exercise. Doctors say it is good for us. It makes your head and body strong. And you
will feel better about yourself. It's best to exercise 1 each week. Twenty minutes each time is 2 . There
are many 3 to exercise. You can walk, run, play sports, or swim. Many people go to 4 places to
exercise. They are 5 "fitess centres." Exercise can be fun. Friends can exercise together at a fitness
centre. Or, they can play sports together. How do you exercise?

1. _____ 2. _____ 3. _____ 4. _____ 5. _____

判断题

按照《空气和废气监测分析方法》（第四版）中“气相色谱法测定非甲烷烃”的方法，使用的色谱柱为长1m、内径4mm的不锈钢柱。