车辆脱轨更换()的交叉杆; A.全车 B.相关 C.另一转向架 D.脱轨转向架

题型:单项选择题

问题:

车辆脱轨更换()的交叉杆;

A.全车

B.相关

C.另一转向架

D.脱轨转向架

考点:铁路货车车辆检修铁路货车车辆检修综合练习铁路货车车辆检修综合练习题库
题型:单项选择题

Are you a man or a mouse When people ask this question they want to know (1) you think you are a (2) person or a coward. But you will never really know the answer to this question (3) you are tested in real life. Some people (4) they are brave but when they come face to face with real (5) , they act like cowards. Others think of themselves as cowards, but when they meet danger, they act like (6)

Lenny had always thought of himself as a (7) person. He got worried before examinations. He worried about his job and health. All he wanted in life was to be safe and healthy. (8) , on January 15th, 2002, a plane crashed into the Potomac River in Washington. Lenny went to the river to see what was happening. He saw a woman in the (9) water. Lenny did not feel afraid. He kept very (10) and did a very dangerous thing. He jumped into the Potomac, (11) to the woman, and kept her head (12) the water. Seventy-eight people died that day. Thanks to Lenny, it was not (13) .

When you are in a very (14) situation and feel afraid, the body automatically produces a chemical in the blood. The chemical is called adrenalin. (15) adrenalin in the blood system, you actually feel per and per and are (16) to fight or run away. However, when you are absolutely terrified, the body can produce too much adrenalin. When this (17) , the muscles become very hard and you find you (18) move at all. You are then paralyzed with fear. This is (19) when we are very frightened, we sometimes say we’re "petrified". This word comes from the Greek word "petros", which means "stone". We are (20) frightened that we become stonelike.

20()

A.really 

B.very 

C.such 

D.so

题型:单项选择题

为了节能环保,王老师骑电动自行车上班,下表是他的电动自行车的有关数据:

王老师以5m/s的速度匀速从学校回到家,用了20分钟,求:

(1)学校到王老师家的路程和电动自行车牵引力所做的功;

(2)电动自行车电能转化为机械能的效率;

(3)目前,我国电动自行车的拥有量已超过1.2亿辆,它给我们出行带来便捷的同时,也导致交通事故频发,针对这一现象请提出一条合理化建议。

题型:单项选择题

二氧化碳气体保护焊时,所用二氧化碳气体的纯度不得低于()

A.80%

B.99%

C.99.5%

D.95%

题型:单项选择题

胆碱的生理功能不包括()。

A.促进体内乙酰基代谢

B.促进脑发育并提高记忆力

C.促进脂肪代谢防止脂肪异常积聚

D.构成生物膜的重要成分从而保证细胞膜的功能

E.调控细胞凋亡,抑制癌细胞增殖

题型:单项选择题

按材料分,蜗壳有两种类型,分别为()。

A.金属蜗壳

B.混凝土蜗壳

C.塑料蜗壳

D.预应力蜗壳

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