等温效率表示实际压缩过程接近等温过程的程度，越接近等温过程，等温效率越低。

阅读理解。

    Sally was a student. It was going to be her mother's birthday. She wanted to buy her a present that

would be nice and useful but not expensive. A week before her mother's birthday, she went shopping

after a quick and simple lunch. When she had been looking for half an hour, she found a shop that was

selling cheap umbrellas (伞), and decided to take a black one, since her mother had lost hers the month

before.

    She thought, "You could carry that when you are wearing clothes of any color." So she decided to

buy a lovely black umbrella and took it back to school with her until her classes had finished.

    On her way back home in the train that evening, she felt hungry because she had such a small lunch

that she went along to the buffet car (餐车) for another sandwich and cup of coffee. She had left the

black umbrella above her seat in the compartment (车厢), but when she got back, it had gone! When

she had left the compartment, there had been no other passengers (乘客) in it, but now there were three.

    Sally began to cry when she saw that the umbrella was no longer there. The other passengers felt very

sorry for her and asked what the matter was. She told them that the black umbrella she had bought for

her mother was gone, and that she had to get out at the next station. After the three other passengers

heard it, they asked her for her mother's address so that they could sent the umbrella to her if someone

had taken it by mistake and brought it back after Sally had got out of the train.

    The next week, Sally heard from her mother. It said, "Thank you very much for your lovely presents,

but why did you send me three black umbrellas?"

1. Which of the following is the best for the sentence "You could carry that when you are wearing clothes

    of any color?" [ ]

A. You can carry it when you are wearing any clothes.

B. Any color of your clothes will be all right.

C. The umbrella will be OK for your clothes in any colors.

D. You can take any clothes that you like to wear.

2. What does the story infer (推断)? [ ]

A. Her mother would write to her if she didn't receive the presents.

B. The three umbrella were sent by the girl.

C. Only four people had ever been to the compartment.

D. Nobody brought the umbrella back.

3. How many umbrellas did Sally's mother get at last?[ ]

A. No.

B. Only one.

C. Three.

D. Four.

4. The best name of the story is ______. [ ]

A. A Lucky Girl

B. The Missing Umbrella

C. A Happy Mother

D. Mother's Present

5. What does the writer want to tell us? [ ]

A. You should take care of your things when you are traveling.

B. Show your love to others, and they will bring you love.

C. Children should often come back to see their parents.

D. It's no use crying when you are in trouble.

已知集合A={（x，y）|y=lg（x+1）-1}，B={（x，y）|x=m}，若A∩B=∅，则实数m的取值范围是（　　）

A．m＜1

B．m≤1

C．m＜-1

D．m≤-1

在保安服务工作中，当发生重大案件或事故时，应急处臵的第一道程序是（）。

A.报告公安机关和单位领导

B.维护现场及周边秩序

C.向周围人员求援

D.紧急进入现场处臵

使用通胀扩径法修复套管常用的下井工具有哪些？

加热炉工作压力大于2.5MPa时，压力表精度等级应高于（）级。

A、2.5

B、1.5

C、1.0

D、0.5