牵引电动机由全磁场向一级磁场削弱的转换过程,称为()。A、一级正向过渡 B、二级正向

题型:单项选择题

问题:

牵引电动机由全磁场向一级磁场削弱的转换过程,称为()。

A、一级正向过渡

B、二级正向过渡

C、一级反向过渡

D、二级反向过渡

考点:铁路职业技能鉴定考试高级内燃机车司机高级内燃机车司机题库
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他常说:“提出一个问题往往比解决一个问题更重要。”当大多数物理学家沿着牛顿的道路继续前行时,他却走上了一条创新之路,最终提出了物理学的相对论,对牛顿的力学体系和绝对时空观进行了根本性的变革。他是[ ]

A、

   牛顿

B、

        达尔文

C、

    法拉第

D、

    爱因斯坦

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男性,25岁,体健。主诉:牙龈自动出血伴牙龈疼痛、腐败性口臭5天

此患者首次最佳治疗措施是()

A.去除大块牙石及坏死物冲洗

B.尽量除净牙石及坏死物冲洗

C.口服抗生素及维生素C

D.保守治疗,需查血确诊

E.1%~2%双氧水含漱1周

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Mr. Ma, a famous mental doctor from Beijing once said at an important meeting, “Now many young students can have many problems with their minds. Some students become worried because they have to study very hard. Others have trouble getting on well with people around them like their parents and classmates. Parents and teachers should care more about this problem.”

Then Mr. Ma gave some examples. One patient, a middle school student from Xi’an was doing badly in his lessons. He thought his teachers and friends often laughed at him, and he became so nervous and worried that one night he left his home without telling parents. Another student, a 14-year-old schoolgirl from Shanghai, was very afraid of exams. While she was reading the exam paper, she couldn’t think of anything to write.

A recent report from Jiefang Daily says about 18% of the young students in Shanghai have mental problems. They often fell worried and very unhappy. Unluckily, many of them won’t go and ask for help. Some think they will look stupid if they go to see a doctor. Others won’t talk about their own secrets.

At the end of the meeting, Mr. Ma offered some good ideas to young people:

◆Talk to your parents or teachers often.

◆Take part in group activities.

◆Try to get along well with the people around you.

◆Go to see a doctor if you often feel unhappy.

小题1:The students who often become worried or have trouble getting on with others may have ______.

A.no parents

B.no secrets

C.poor memories

D.mental problems小题2:The schoolgirl’s problem happened whenever she __________.

A.studied very hard

B.had exams

C.talked with her parents

D.went to see the doctor小题3:Some of those with mental problems won’t ask for help because ______________,

A.they don’t want to tell their secrets to others

B.their parents are too busy to look after them

C.doctors can’t help them with the problems

D.they can do with the problems themselves小题4: According to the last part, which of the following is a good idea?

A.It’s important for children to live with their parents.

B.It’s helpful for people to see doctors every day.

C.It’s useful for students to keep quiet in class.

D.It’s necessary for young people to have group activities.

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用附加零件法修理零件的优缺点是什么?

题型:单项选择题

煤与瓦斯突出危害主要表现在()个方面。

A.一

B.两

C.三

D.四

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