试题与答案

如图所示,气缸的质量为M,活塞的质量为m,活塞与气缸壁之间无摩擦、与外界无热交换

题型:选择题

题目:

如图所示,气缸的质量为M,活塞的质量为m,活塞与气缸壁之间无摩擦、与外界无热交换且不漏气,气缸中密封了一部分理想气体,最初气缸被销钉固定在足够长的光滑固定斜面上.现拔去销钉,让气缸在斜面上自由下滑,当活塞与气缸相对静止时,被封气体与原来气缸静止在斜面上时相比较,下列说法正确的是(  )

A.气体的压强不变

B.气体的内能减少

C.气体的温度升高

D.气体的体积减小

答案:

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题型:阅读理解

阅读理解。

     As the sun rose, a dewdrop (露珠) woke up.  There it sat on a leaf, catching the sunlight. Proud of its

simple beauty,  it was very happy.  Around it were other dewdrops,  some on the same leaf and some on

other leaves. The dewdrop was sure that it was the best, the most special dewdrop of them all.

     Ah, it was good to be a dewdrop.

     The  wind  blew  and  the plant began to shake,  tipping  (使倾斜)  the leaf . The  dewdrop  became

frightened as it started to move towards the edge (边缘)of the leaf. Why was this happening? Things were comfortable. Things were safe. Why did they have to change? Why? Why?

     The dewdrop  reached  the edge of th e leaf.  It was sure that this was the end.  The day had only just

begun and the end had come so quickly. It seemed so unfair. It seemed so meaningless. It tried hard to do whatever it could to stay on the leaf, but it was no use.

     Finally, it fell. Below there was a mirror. A reflection of the dewdrop seemed to be coming up to meet

it.  Closer and closer they came together until finally.., the small dewdrop became a part of the great pond (池塘). Now the dewdrop was no more, but it was not destroyed. 

     It had become one with the whole.

1. According to Paragraph 1, we know that the dewdrop _____.

A. didn't get on well with other dewdrops

B. thought its beauty was too simple

C. couldn't get any sunlight

D. thought itself as the best dewdrop

2. The dewdrop became _____ as it started to move towards the edge of the leaf.

A. scared

B. happy

C. proud

D. comfortable

3. Which of the following is TRUE according to the story?

A. There was only one dewdrop on the leaf.

B. The dewdrop did nothing before falling.

C. The mirror in the story refers to the pond.

D. The dewdrop was actually destroyed.

4. What does the underlined word "reflection" mean?

A. 反映

B. 考虑

C. 沉思

D. 倒影

5. The story mainly tells us that _____.

A. we should work together against difficulties

B. people should not be too proud of themselves

C. one should work hard for his/her goals

D. it's good to become one with the whole

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