问题 问答题 简答题

直流锅炉切除分离器时会发生哪些不安全现象?是什么原因造成的?

答案

参考答案:

(1)切除启动分离器时,极易发生主汽温度下降和前屏过热器管壁超温现象。

(2)启动过程中应严格按照启动分离器切除的条件执行操作。若切除过早,分离器过早停止排水,使蒸发段出口工质焓值降低,同时过热器内蒸汽流量增大,易造成过热汽温降低。若切除过迟,则会使前屏过热器管壁超温。

单项选择题
阅读理解

In the past ten years, many scientists have studied the differences between men and women. And they all got the same answer: The sexes are different, because their brains are different. And this, the scientists say, makes men and women see the world in different ways.

Boys, for example, generally are better than girls at mathematical ideas. Boys also generally are better than girls at the kind of hand and eye movements necessary for ball sports. Girls, on the other hand generally start speaking earlier than boys. And they generally(通常)see better in the dark than boys and are better at learning foreign languages.

What makes men and women better at one thing or another? The answer is the brain. The brain has two sides connected by nerve(神)tracks. The left side generally is used for mathematics, speech and writing. The right side is used for artistic creation and the expression for emotions(情感). In men and women, different areas in each side of the brain develop differently. In boys, for example, it’s the area used for mathematics. In girls, it is the area used for language skills. Another interesting difference is that the two sides of a man’s brain are connected by a smaller nerves than the two sides of a woman’s brain are.

小题1:Which of the following is best to outline(概括)the article?

A.Research on the Brain

B.Differences between Men and Women

C.People’s Different Brains

D.Who Are Better, Boys or Girls小题2:______ men and women think differently.

A.Sex makes

B.The different brains make

C.The different experiences make

D.The influences of society make小题3:According to the article, girls are generally better than boys at ______ in your school.

A.Mathematics

B.Physics

C.English

D.Chemistry小题4:Which of the following is true?

A.The left side of brain in boys generally develops better than that in girls.

B.The left side of brain in girls generally develops better than that in boys.

C.Men are better than women in all things.

D.The area in girls used for language skills develops better.小题5:In men and women the number of nerves connecting the halves of brain _______.

A.is the same

B.is different

C.is zero

D.can’t be found out