问题
多项选择题
以下选项中，关于离心泵抽空的原因说法正确的有（）。
A、泵内或入口管线有存气
B、吸入阻力太大或灌注高度大
C、油品温度过高，泵内汽化
D、泵的转速高
答案
参考答案：A, C
搜题请搜索小程序“爱下问搜题”
以下选项中，关于离心泵抽空的原因说法正确的有（）。
A、泵内或入口管线有存气
B、吸入阻力太大或灌注高度大
C、油品温度过高，泵内汽化
D、泵的转速高
参考答案：A, C
| 完形填空。 | ||||
| I still remember I fell in love with English from a very young age, because I thought it was such a(n) 1 language. Full of strong wishes of learning English, I began to 2 it. But soon I found it 3 than expected. There were too many words, expressions and many other things to remember. And even if you know 4 , you can't use them correctly and exactly. And I did rather 5 in my first English test. I was worried about it. This made me upset and dropped my interest in English 6 . While I was in trouble, my English teacher gave me much help. I knew that ininterest didn't mean 7 and I should have some learning methods. I did as he said and tried many different ways of learning English. 8 the days went by, I could do better and better and became more and more interested in it. During summer vacation, an old lady from Australia visited my school. She had a talk with us. It was the first time 9 a foreigner. I got 10 nervous at first, but soon I found it exciting to talk with her, and I learned a lot from her. How I wish to practice speaking English with foreigners every day! | ||||
|
