问题 问答题 简答题

二段蒸发用舒适方法提高冷凝温度的?为什么提高?冷凝温度就可以冷凝下来,开车时何时开升压泵?

答案

参考答案:

二段蒸发压力较低,二段不能靠循环水直接冷凝,故要升高压力,即用升压泵把二段分离气相压力由0.0034MPa升高到0.012MPa,此时蒸汽冷凝温度为49,用32℃循环水就可以冷凝了,当PR404达到600-650mmHg时开升压泵。

阅读理解

阅读理解。

     Excuses!  Excuses !

     Harry was often late for school, and when the teacher asked him why he was late

he always had an excuse. " My alarm clock didn't go off,"  he said one morning. "The bus broke down, "he told her another morning. Usually he just didn't want to get out

of bed!

     When he didn't hand in his homework he had an excuse for this as well. "The dog ate it,"was one reason that he had forgotten to do it, or left it until he was too tired. He always thought of someone or something to blame for his mistakes.

     "Why are your grades so bad, Harry?" his mother asked him one afternoon.

      "It's not my fault (错误) , Mom,"Harry replied.

     "My teacher isn't very good. "

     "Then I will phone the school and talk to your headmaster, " his mother said.

      "No , no. " Harry said quickly. "That won't help. He doesn't like me."

      "Then we'll have to send you to a different school, " his father said, " You won't

see your friends anymore but your grades are more important. "

      Harry thought about this for a minute. He didn't want to change schools. Then he said, "I probably could try harder to get to school on time. "

      "That would help, " his  mother replied. "But what  about your homework?"

        "Well, "he said. "I suppose l could work harder to keep up with my homework

as well. I think I'll  go and do today's homework right now. "

     When Harry left the room, his father said to his mother , " That  wasn't  too  

difficult , was  it? "   

1. What is the main idea of this passage?

A. Harry's mom and dad thought Harry should change schools.

B. Harry's mom and dad thought Harry should try harder at school.

C. Harry decided to stop making excuses and work harder at school.

D. Harry decided to do his homework.

Complete the following sentences with the words or phrases in the passage.

2. You shouldn't        other people for your mistakes.

3. If you can't        your work you should ask your teacher for help.

4. Bill's          for forgetting his mom's birthday was that he lost his diary.

5. We had to         our homework to the teacher.

判断题