题目:
齿轮泵主要振动原因有那些?
答案:
参考答案:
①泵与电机不同心;②主动轮与从动轮平行度超差;③泵内进杂物;④安装高度过高,介质吸不上;⑤地脚螺栓松动。⑥轴承磨损间隙过大;⑦轴弯曲;⑧吸入空气;⑨齿轮磨损;⑩键槽损坏或配合松动。
齿轮泵主要振动原因有那些?
参考答案:
①泵与电机不同心;②主动轮与从动轮平行度超差;③泵内进杂物;④安装高度过高,介质吸不上;⑤地脚螺栓松动。⑥轴承磨损间隙过大;⑦轴弯曲;⑧吸入空气;⑨齿轮磨损;⑩键槽损坏或配合松动。
2002年发布的《全国银行间债券市场债券交易规则》规定,全国银行间债券市场回购期限最长为( )天。
A.91
B.180
C.360
D.365
李萍看一本故事书,3天看了24页,照这样计算,全书共216页,还要( )天才能看完。
阅读理解。
However important school life may be, we can't ignore the fact that children spend more
time at home than in the classroom. Therefore the great influence of parents can't be ignored
or discounted by the teacher. They can become strong supports of the school or they can
consciously or unconsciously prevent the school from accomplishing its aims.
Administrators have been aware of the need to keep parents apprised of the newer methods
used in schools. Many principals have conducted workshops explaining such matters as the
reading readiness program and developmental math.
Moreover, the classroom teacher can also play an important role in explaining to parents what
they should do. The informal tea and many interviews carried on during the year, as well as new
ways of reporting pupils' progress, can significantly aid the interchange of ideas between school
and home.
Suppose that a father has been drilling Junior in arithmetic processes night after night. In a
friendly interview,the teacher can help the parent change his method. He might be persuaded to
let Junior participate in discussing the family budget, buying the food, using a measuring cup at
home, setting the clock, calculating mileage on a trip and engage in scores of other activities that
have a mathematical basis.
If the father follows the advice, it is reasonable to assume that he will soon realize his son is
making satisfactory progress in math and at the same time, enjoying the work.
Too often, however, teachers' conferences with parents are devoted to unimportant accounts
of children' s wrongdoing,complaints about laziness and poor work habits, and suggestions for
punishments and rewards at home.
What is needed is a more creative approach in which the teacher, as a professional advisor, plants
ideas in parents' minds for the best use of the many hours that the child spends out of the classroom.
In this way, the school and the home join forces in fostering the fullest development of youngsters'
competence.
1. The underlined phrase "keep parents apprised of" in Para.2 probably means to let
parents _____. [ ]
A. judge
B. know
C. design
D. develop
2. What is the purpose of the schools' informal tea and interviews? [ ]
A. To improve the relationship between teachers and parents.
B. To explain to parents the change of the school curriculum.
C. To report students' misdoings and suggestions for punishments.
D. To help develop good communication between school and home.
3. Why does the author provide the example in Paragraph 4? [ ]
A. To help parents know the importance of home activities.
B. To show how the teacher can guide in home training.
C. To prove parents are non-professional advisors.
D. To advice parents to teach kids math at home.
4. From the passage we learn that the author _____. [ ]
A. thinks teachers should do better as professionals
B. is worried about children' s performance at home
C. is satisfied with the present state of school education
D. believes time spent out of the classroom has been wasted
根据《公司法》规定,有限责任公司的注册资本可以分期缴纳,股东可以最低限额3万元的20%,即6000元作为首次出资额。 ( )
我国在环境噪声污染防治方面颁布的第一个综合性环境噪声质量保准是()。