什么是锅炉汽温的静态特性?

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问题:

什么是锅炉汽温的静态特性?

考点:集控值班员考试锅炉调节锅炉调节题库
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燃煤采样中子样有哪几种可能的配置方式?

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Do you know why different animals or pests (昆虫) have their special colors? Colors in them seem to be used mainly to protect themselves.

  Some birds like eating locusts (蝗虫), but birds cannot easily catch them. Why? It is because locusts change their colors together with the change of the colors of crops(庄稼). When crops are green, locusts look green. But as the harvest time comes, locusts change to the same brown color as crops have. Some other pests with different colors from plants are easily found and eaten by others. So they have to hide themselves for lives and appear only at night.

If you study the animal life, you’ll find the main use of coloring is to protect themselves. Bears, lions and other animals move quietly through forests. They cannot be easily seen by hunters (猎人). This is because they have the colors much like the trees.

Have you ever noticed an even stranger act? A kind of fish in the sea can send out a kind of very black liquid (液体)when it faces danger. While the liquid spreads over (散开), its enemies (敌人)cannot find it. And it immediately swims away. So it has lived up to now though it is not strong at all.

36. From the passage we learn that locusts________.

A. are small animals                  B. are easily found by birds

C. are dangerous to their enemies    D. change their colors to protect themselves

37. How can pests with different colors from plants keep out of danger?

A. They run away quickly.         

B. They have the colors much like their enemies.

C. They hide themselves by day and appear at night.      

D. They have to move quietly.

38. Bears and lions can keep safe because _________.

A. they have the colors much like the trees     B. they move quietly

C. they like brown and gray colors            D. they live in forests

39. Why can the kind of fish live up to now?

A. Because it is very and strong.    

B. Because the liquid it sends out can help it escape from its enemies.

C. Because the liquid it sends out can kill its enemies.

D. Because it swims faster than any other fish.

40. Which is the best title for this passage?

A. The Change of Colors for Animals and Pests   

B. Colors of Different Animals and Pests

C. The Main Use of Colors for Animals and Pests  

D. Some Animals and Pests

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The key word in the sentence has been ______, so it doesn't make any sense to us. [ ]

A. picked up    

B. left out      

C. held up      

D. made out

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主站与子站间通常采用的通信方案是()。

A、单模光纤

B、多模光纤

C、自愈式单环

D、自愈式双环

题型:问答题 简答题

地下建筑防水设计的下列论述中,哪一条有误().

A.地下建筑防水材料分刚性防水材料和柔性防水材料 

B.地下建筑防水设计应遵循“刚柔相济”的原则 

C.防水混凝土、防水砂浆均属于刚性防水材料 

D.防水涂料、防水卷材均属于柔性防水材料

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