相关试题
【判断题】
[154]启动时，汽轮机部件的温度、汽缸内压力、机组转速都在不断升高，部件被蒸汽逐步加热直至稳定热平衡的过程是蒸汽
【判断题】
[155]超速跳车转速（转/分），以设备铭牌或使用说明书要求为准，如无要求，则该转速设定应至少为最高连续转速，且不大于127%。
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[156]所有的特护机组均包括主机、驱动机、附属机械。
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[157]泵是用来增加液体能量的机器，它可以输送、提升液体或将液体送入压力窗口容器。
【判断题】
[158]实际使用的压缩机在出口管道靠近压缩机的地方都装有止逆阀，故使其振幅大大地增大，但脉动的频率随之减少。
【判断题】
[159]三机停车后都要进行盘车，以防止静止时发生轴弯曲。
【判断题】
[160]三台透平压缩机组最高操作压力为11.97MPa，最低温度为-101.3℃。
【判断题】
[161]复水器的液位控制采用串级调节。
【判断题】
[162]为节约能量，乙烯精馏塔在提馏段设置中间再沸。
【判断题】
[163]降低乙烯精馏塔和压力，可增大乙烯
【判断题】
[164]逆可诺循环是一种理想的制冷循环。
【判断题】
[165]裂解气压缩机透平V2阀开度越大，抽汽量越大。
【判断题】
[166]电子调速器跳车后压缩机不一定跳车。
【判断题】
[167]裂解气压缩机透平的调速油返回线不直接回油箱且与润滑油回油不相连。
【判断题】
[168]乙烯机透平轴位移联锁值为±500um。
【判断题】
[170]裂解气压缩机段间吸入温度高时将引起二烯烃聚合。
【判断题】
[171]只有碱洗才能除去酸性气中的有机硫。
【判断题】
[172]离心泵一般转速为1450转/分或2950转/分。
【判断题】
[173]往复压缩机压力范围广，从低压到超高压范围都适用，而离心式压缩机
【判断题】
[174]两台泵并联工作时，在相同扬程下，并联后泵的流量为单台泵的两倍。
【判断题】
[175]产品乙烯送出装置的压力和流量变化，
【判断题】
[176]干燥器再生步骤中冷吹的目的是用甲烷把流体汽化解吸。
【判断题】
[177]设备打开检修前，必须要经过倒空置换，加盲板、鼓风等安全措施。
【判断题】
[178]裂解气压缩机系统“五返五”只为防喘振而设计。
【判断题】
[179]要减少乙烯损失，必须控制好分馏分凝器顶部温度。
【判断题】
[180]新鲜碱中含有Fe和氧气将增加聚合物的形成。
【判断题】
[181]若精馏操作不正常，引起塔顶产品中重组分浓度增加时，可采用适当提高操作压力的办法，使产品质量合格。
【判断题】
[183]可燃物质在空气中的含量低于爆炸下限时，遇到明火，既不会燃烧，也不会爆炸。
【判断题】
[184]皮肤上溅到碱液后应立即用大量水冲洗。
【判断题】
[185]相等体积的任何气体都含有相同数目的分子。
【判断题】
[186]裂解气中的硫化氢主要来自原料中的有机硫化物在裂解过程中与氢发生反应而来。
【判断题】
[187]当压缩机吸入流量一定时，若入口压力增加，则出口压力也增加。
【判断题】
[188]降低吸入温度可降低压缩机功耗。
【判断题】
[189]减少段间压降可降低压缩机功耗。
【判断题】
[190]油冷却器出口温度不能低于40℃。.
【判断题】
[191]压缩机停车后还要继续油运24小时，直至轴承温度降至正常。
【判断题】
[192]压缩机组的润滑油只能起润滑作用。
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50.___基础是指桩，墩，沉井，沉箱和地下连续墙等基础。
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51.按桩的施工方法，桩分为___和___两类。
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【单选题】
The word "wag" (Line 1, Para.1) most probably means _________.
A. move
B. shake
C. bite
D. play
【单选题】
The video cameras were used to catch the dogs' responses because ___________.
A. the dogs were put in the wooden boxes
and tested one at a time
B. it was easier to catch the dogs’s response changes in the tail wagging
C. they enabled the dogs’owners to know
about their dogs’; habit
D. the dogs wagged their tails in different
directions when they were in different
moods
【单选题】
When there are no stimuli, a dog will ___________.___
A. wag to the right
B. no wag at all
C. wag to the left
D. wag to the left and then wag to the right
【单选题】
The purpose of doing the experiment is _________.___
A. to train dogs for their owners
B. to help dogs find companion
C. to help people choose their pet dogs
D. to help people judge the mood of dogs
【单选题】
The underlined word "they" in the last sentence refers to __________.___
A. the trainers
B. the systems
C. the researchers
D. the dogs
【单选题】
The new law passed in Rome will ________.___
A. help improve fishing environment
B. stop people from catching goldfish
C. guarantee better conditions for goldfish
D. discourage keeping goldfish at home
【单选题】
People in Rome believe that the civilization of a city can be judged by _________.___
A. awareness of animal protection
B. exchanges with other cities
C. protection of ancient ruins
D. recognition of animal lovers
【单选题】
The underlined word "compassion" in Para 2 is the closest in meaning to __________.___
A. support
B. pity
C. help
D. love
【单选题】
People may break the law in Turin if they ________.___
A. keep their dogs or cats in cars
B. shut their dogs home all day long
C. raise their cats near ancient ruins
D. feed homeless animals in car parks
【单选题】
We can infer from the passage that _________.___
A. the owners can leave their dogs in hot cars
B. the cat only lives in modern life
C. the new law can prevent cruelty to animals
D. the new law gives recognition to the
people who feed homeless cat
【单选题】
If a person finds getting up early a problem, most probably ________.___
A. he is a lazy person
B. he refuses to follow his own energy cycle
C. he is not sure when his energy is low
D. he is at his peak in the afternoon or evening
【单选题】
Which of the following may lead to family quarrels according to the passage?___
A. Unawareness of energy cycles.
B. Familiar monologues.
C. A change in a family member's energy cycle.
D. Attempts to control the energy cycle of other family members.
【单选题】
If one wants to work efficiently at his low point in the morning, he should __________.___
A. change his energy cycle
B. overcome his laziness
C. get up earlier than usual
D. go to bed earlier
【单选题】
You are advised to rise with a yawn and stretch because it will __________.___
A. help to keep your energy for the day's work
B. help you to control your temper early in the day
C. enable you to concentrate on your routine work
D. keep your energy cycle under control all day
【单选题】
Which of the following statements is NOT true?___
A. Getting off to work with a minimum effort helps save one's energy.
B. Dr. Kletman explains why people reach their peaks at different hours of day.
C. Habit helps a person adapt to his own energy cycle.
D. Children have energy cycles, too.
【单选题】
An effective way to prevent the burnout of young athletes is __________.___
A. to increase their sense of success
B. to make sports less competitive
C. to reduce their mental stress
D. to make sports more challenging
【单选题】
According to the passage sport is positive for young people in that __________.___
A. it can help them learn more about society
B. it enables them to find flaws in themselves
C. it teaches them how to set realistic goals for themselves
D. it can provide them with valuable experiences
【单选题】
Many coaches and parents are in the habit of criticizing young athletes __________.___
A. without realizing criticism may destroy their self-confidence
B. in order to make them remember life's lessons
C. believing that criticism is beneficial for their early development
D. so as to put more pressure on them
【单选题】
According to the passage parents and coaches should __________.___
A. help children to win every game
B. pay more attention to letting children enjoy sports
C. train children to cope with stress
D. enable children to understand the positive aspect of sports
【单选题】
The author's purpose in writing the passage is _________.___
A. to persuade young children not to worry about criticism
B. to stress the importance of positive reinforcement to children
C. to discuss the skill of combining criticism with encouragement
D. to teach young athletes how to avoid burnout
【单选题】
As pointed out at the beginning of the passage, people used to think that air pollution _______.___
A. cause widespread damage in the countryside
B. affected the entire eastern half of the United States
C. had damaged effect on health
D. existed merely in urban and industries areas
【单选题】
As to the greenhouse effect, the author ________.___
A. share the same view with the scientist
B. is uncertain of its occurrence
C. rejects it as being ungrounded
D. thinks that it will destroy the world soon
【单选题】
The underlined word "offset" in the second paragraph could be replaced by _________.___
A. slip into
B. make up for
C. set up
D. catch up with
【单选题】
It can be concluded that ____________.___
A. raising the world's temperature only a few degrees would not do much harm to life on earth
B. lowering the world's temperature merely a few degrees would lead major farming areas to disaster
C. almost no temperature variations have occurred over the past decade
D. the world's temperature will remain constant in the years to come
【单选题】
This passage is primarily about __________.___
A. the greenhouse effect
B. the burning of fossil fuels
C. the potential effect of air pollution
D. the likelihood of a new ice age
【单选题】
What is the major function of paragraph 1?___
A. To arouse the reader's concern.
B. To introduce the theme of the whole passage.
C. To summarize the whole passage.
D. To state the primary uses of TV.
【单选题】
Television, as a source of entertainment, is ________.___
A. not very convenient
B. very expensive
C. quite dangerous
D. relatively cheap
【单选题】
Why are some people against TV?___
A. Because TV programs are not interesting.
B. Because TV viewers are totally passive.
C. Because TV prices are very high.
D. Because TV has both advantages and disadvantages.
【单选题】
One of the most obvious advantages of TV is that _________.___
A. it keeps us informed
B. it is very cheap
C. it enables us to have a rest
D. it controls our lives
【单选题】
According to the passage, whether TV is good or not depends on ___________.___
A. its quality
B. people's attitude towards it
C. how we use it
D. when we use it
