相关试题
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位置公差就是实际位置对理想位置的允许变动量。
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表面结构一般受加工方法或其他因素影响。
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在曲柄摇杆机构中，传动角越大。机械的传力性能越好。
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行程速比系数K表示机构的急回特性，K值越大，急回特性就越明显。
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车床主轴箱中的滑移齿轮不属于变向机构。
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等加速、等减速的凸轮机构，应用于凸轮转速较高和从动杆质量较大的场合。
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轮系中加入惰轮，可改变从动轮的旋转方向，并改变主、从动轮的传动比大小。
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所有轮系的齿轮轴的几何位置都是固定的。
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在行星轮系中，行星轮的轴线是转动的，但只能自转而不能公转。
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两带轮直径之差越大，则包角越小，所以传动比不宜过小。
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V带传动的张紧轮应尽量靠近大带轮的一边。
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在外径千分尺螺旋传动结构中，螺母不动，丝杆回转并做直线运动。
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在螺旋传动中，螺杆与螺母之间只有滑动摩擦。
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所有的螺旋传动都是效率较低的，因为它属于滑动摩擦。
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蜗杆传动适用于传动比大而只需传递较小功率的机器中。
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蜗杆传动与齿轮传动一样，能保证传动比的准确性。
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在链传动中，当链轮转速越高、链节距越大时，动载荷就越小。
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渐开线上各点的曲率半径是变化的，离基圆越远其曲率半径越小。
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在制造变位齿轮时，一般都是把大齿轮作为变位齿轮的。
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齿轮传动的传递功率范围较小，但效率较高。
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标准直齿圆柱齿轮的分度圆直径与齿数无关。
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螺纹连接中，螺钉或螺母的螺距一般采用细牙螺纹。
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压强是液体在静止状态下单位面积上所受到的作用力。
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液压缸系统中因运动速度较低，故无须安装缓冲装置。
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由于管道截面形状的突然变化和液体流向的突然改变引起的压力损失，称为沿程损失。
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【单选题】
Poor Laura! I feel so sorry for her. When she fell, she hurt her arm and, ___, broke her glasses.
A. in advance
B. in addition
C. over time
D. on the other hand
【单选题】
Showing some sense of humor can be a(n) ___ way to deal with some stressful situations.
A. genuine
B. available
C. effective
D. favorite
【单选题】
It will be worth the efforts even if you fail; the rewards you ___ will be great.
A. reap
B. boast
C. assure
D. cultivate
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He suggested transporting the supplies by air. But it is absolutely ___, for it will cost too much.
A. unusual
B. uncertain
C. impractical
D. impressive
【单选题】
The newspaper didn’t mention the ___ of the damage caused by the fire.
A. range
B. level
C. extent
D. quantity
【单选题】
Do you ___ her novels as serious literature or as mere entertainment?
A. classify
B. notify
C. simplify
D. justify
【单选题】
He doesn’t ___ of buying a house this year because the bank has refused to lend him any money.
A. afford
B. make the most
C. run out
D. stand a chance
【单选题】
If you don’t ___ cooking today, we can go out to eat at the new restaurant.
A. would like
B. go on with
C. feel like
D. figure out、
【单选题】
Bullying (恃强欺弱) can ___ a climate of fear and anxiety in school, and prevent students from focusing on their schoolwork.
A. keep back
B. give rise to
C. feel like
D. make use of
【单选题】
Science can now ___ many things which were thought to be mysterious by ancient people.
A. care for
B. lay out
C. account for
D. set up
【单选题】
The school has ___ many after-class activity groups for the pupils to make their spare time more colorful.
A. set up
B. set off
C. set out
D. set down
【单选题】
When he was a small kid, he ___ from his peers because he could read fast and remember whatever he rea D.
A. showed off
B. worked out
C. stood out
D. straightened up
【单选题】
The fall in the number of deaths from heart disease is generally ___ improvements in diet.
A. put up with
B. attributed to
C. added to
D. replaced with
【单选题】
We can be partners for now, but ultimately you have to ___ to develop a new software for our project.
A. keep up
B. fire off
C. make sense
D. take the lead
【单选题】
Emotional Intelligence (情商) could be of practical use in many ___ such as how companies decide which job applicant to hire, how parents should raise their children, how schools should teach the students, and so on.
A. aspects
B. disciplines
C. structures
D. opportunities
【单选题】
The teacher should praise students for their correct answers and also suggest ___ possibilities.
A. unlimited
B. unique
C. alternative
D. essential
【单选题】
In some classrooms, desks are arranged in a U-shape, so the teacher can ___ easily with the students.
A. interrupt
B. interact
C. interpret
D. interview
【单选题】
Computer technology ___ individuals to educate themselves and adapt to a constantly changing job market.
A. lets
B. makes
C. enables
D. provides
【单选题】
Our hope for an enjoyable dinner was instantly ___ when the waiter dropped a salad plate on my hea D.
A. spoiled
B. restricted
C. exploded
D. vanished
【单选题】
___ the world has ever seen has occurred in the information and communications technologies.
A. Great a change
B. The great change
C. A greatest change
D. The greatest change
【单选题】
___ so many people around, it wasn’t convenient to have a long talk with him.
A. As
B. When
C. With
D. Since
【单选题】
Alice used to be terribly shy, but working abroad for a year has completely ___ her.
A. solved
B. transformed
C. characterized
D. regulated
【单选题】
Chinese Mandarin (普通话) is ___ for foreigners to learn because the changes in the tone will totally change the meaning of words.
A. difficult
B. accessible
C. competitive
D. easy
【单选题】
Take action on those things that will have the biggest ___ impact on your life with the least amount of effort.
A. portable
B. positive
C. sophisticated
D. moderate
【单选题】
The adoption of this measure will greatly reduce the ___ of greenhouse gas emissions (排放物), which may help slow global warming.
A. loan
B. decline
C. release
D. response
【单选题】
I think I have a healthy lifestyle. I eat a lot of fruit and vegetables, and I’m a ___ drinker.
A. moderate
B. heavy
C. gradual
D. delicate
【单选题】
In a way the human race needs to improve its mental and physical qualities if it is to deal with the more and more ___ world and meet new challenges.
A. typical
B. complex
C. rational
D. orderly
【单选题】
If a person simply does not care about this activity, it’s ___ impossible to get him to participate.
A. barely
B. seldom
C. hardly
D. practically
【单选题】
Sometimes, even when the mind ___ functioning, the body keeps on working normally.
A. ceases
B. arouses
C. regulates
D. specializes
【单选题】
Jeffery expressed his ___ about the health and fitness of his co-workers, but they said they didn’t want to “waste time” on an exercise bike or jogging.
A. agony
B. concern
C. addiction
D. feedback
【单选题】
Such chemicals are indeed negatively ___ those humans to whom they are expose D.
A. risking
B. detecting
C. impacting
D. overwhelming
【单选题】
We regret for selling you the faulty product, and our company has agreed to ___ you by $500.
A. match
B. reverse
C. reward
D. compensate
【单选题】
This lecture taught me how to manage my time better to include my online studies in my busy ___.
A. schedule
B. outline
C. structure
D. responsibility
【单选题】
Generally speaking, an Irish person will not accept an offer straight away; he will ___ once or twice first before accepting it.
A. receive
B. decline
C. summarize
D. polish
【单选题】
There is every possibility that many species (物种) of animals will die out because of their disappearing food ___.
A. mode
B. source
C. pattern
D. foundation
【单选题】
As a college student, you should enjoy learning and get yourself ___ in those things that interest you.
A. concerned
B. devoted
C. involved
D. pursued
【单选题】
The name of Hitler (希特勒) has always been associated with war and ___ killing in the minds of those people who lived through World War Two.
A. imaginary
B. multiple
C. indispensable
D. massive
【单选题】
He works hard every day to make more money, but he ___ his health, time with his family, and the hobbies he once love D.
A. neglects
B. reminds
C. ceases
D. Declines
【单选题】
I asked a passenger sitting beside me if our train was the Westlake Express train, and he said he ___ of it.
A. not even heard
B. had not even heard
C. even not heard
D. ever had not heard
【单选题】
Whatever you say in the paper has to ___ your own thinking; hence simply repeating the professor’s opinions or whatever is in the readings will not get you very far.
A. ignore
B. arouse
C. reflect
D. release
