(1)如图1所示,运动员将排球击出,排球离开手后仍在空中继续飞行.不考虑空气阻力

题型:问答题

问题:

(1)如图1所示,运动员将排球击出,排球离开手后仍在空中继续飞行.不考虑空气阻力,请在图中画出此时排球的受力示意图.

(2)画出图2中新型核桃夹手柄受到力F的力臂L.

(3)小东是学校升旗手,他想利用滑轮组来升旗.若将国旗挂在图3中乙轮下的挂钩上,怎样绕绳既可将国旗升上旗杆,又可省力?请在图3中画出你的绕法.

考点:力的示意图
题型:问答题

美国CLIA88将质量控制诸要素归纳为11个方面,它们是:(1)_______(2)_______(3)_______(4)_______(5)_______(6)_______(7)_______(8)_______(9)_______(10)_______(11)_______。

题型:问答题

阅读理解。

     In learning English, one should first pay attention to listening and speaking. It is the groundwork (基础)

of reading and writing. You'd better try your best to speak while you do much listening. Don't be afraid of

making mistakes. But be careful not to let them stop you from improving your English. While you are doing

this, a good way is to write—keep a diary, write notes or letters, and then if you can, ask someone else to

go through (检查) what you have written and tell you what is wrong. Many mistakes in your speaking will

be easily found when you write. Through correcting the mistakes, you can do better in learning English.

     If you are slow in speaking, don't worry. One of the helpful ways is reading, either aloud or to yourself.

The important thing is to choose something interesting to read. It mustn't be too difficult for you. When you

are reading in this way, don't stop to look up the words if you can guess their meanings, or they have nothing

important to do with the sentence. You can look them up later.

1. For the beginners, listening and speaking is _____. [ ]

A. more important than reading and writing

B. not so important as reading and writing

C. as important as reading and writing

D. not so useful in learning English

2. When you are speaking, ______.[ ]

A. you shouldn't make any mistakes

B. you must speak slowly

C. it doesn't matter if you make any mistakes

D. you had better take a dictionary with you

3. One of the good ways to find your mistakes in your speaking is to _____. [ ]

A. speak as much as possible

B. write notes or letters

C. ask some Americans to speak with you

D. read more English books

4. If you want to be fast in speaking, you should choose something _____. [ ]

A. difficult to read aloud

B. easy to read to yourself

C. interesting to read to yourself

D. important to read aloud

5. In reading, if you meet a new word which has something important to do

    with the sentence, you'd better _____. [ ]

A. stop to look it up

B. not look it up and just go on reading

C. stop reading at once

D. not stop to look it up

题型:问答题

铁公路联合运输、电铲转载影响转载台长度的主要因素?

题型:问答题

蛋白质消化率最高的食品是( )

A.馒头

B.米饭

C.乳类

D.大豆

E.肉类

题型:问答题

上缸猫爪结构的优点是承力面与汽缸的水平中分面在一个平面内,能较好地保持汽缸与转子的中心一致。

更多题库