自动变速器中的离合器由哪几部分组成？有何作用？

柠檬酸（三元弱酸）可预防和治疗高血压，将0.1mol/L的柠檬酸水溶液加水稀释，该过程中下列微粒浓度增大的是（　　）

A．柠檬酸分子

B．柠檬酸根

C．H⁺

D．OH^-

下列有关化学用语表示正确的是

A．－CHO的电子式：

B．丙烷分子的比例模型为：

C．2－乙基－1，3－丁二烯的键线式：

D．邻羟基苯甲酸的结构简式：

     We can almost always find an opportunity for kindness. I filled my afternoon with small acts of

kindness today and  they didn't take much time or effort, but I hope they made  a small difference to the

people who received them.

     This afternoon I went out shopping. My first stop was the supermarket. I wanted to buy some bread

with chocolate for my little daughter Rita. After I got the bread, I went on to my second stop-a local

charity (慈善) bookshop. I wanted  to see if I could buy some books on unicorns for Rita.

     While I was there, I started a conversation with the shop assistant, during which she commented on

the smell of my bread. I jokingly replied she could either avoid it (if she was on a diet) or go to the

supermarket and get some. She replied she would prefer the second. "Even better. I will give you mine,"

I said. I gave my bread to her and walked straight  out. She seemed a little surprised.

     When I came out, it was raining hard. Everyone looked  quite soaked. They must have been running

in the rain. I noticed a homeless lady selling the Big Issue (a magazine  that supports homeless people)

and she looked especially cold, so I gave her all my money to buy her magazines.

     I then went back to my car. I had to pay for two hours of parking instead of one because I didn't

have the correct change, so I still had an hour left on my parking. I waited until I saw a young couple

drive in. I gave them one magazine and they were a little surprised and quite pleased.

     You see, doing acts of kindness is that easy.

1. What can we know from Paragraph 1?

A. Being kind to others nowadays is not easy.

B. The writer did some acts of kindness today.

C. The writer does some acts of kindness every day.

D. Kindness always makes a difference to the receiver's life.

2. What do we know about the bookshop mentioned in Paragraph 2?

A. It is a children's bookstore.

B. It mainly sells books about unicorns.

C. It is located in a supermarket.

D. It aims to make money to help others.

3. It is implied in the passage that the shop assistant________.

A. was trying her best to lose weight

B. might like the smell of the bread very much

C. would give the bread to someone homeless

D. expected the writer would give her the bread

4. What does the underlined word "soaked" in Paragraph 4 mean?

A. Strange.  

B. Surprised.  

C. Wet.  

D. Excited.

5. We infer that the writer wrote this passage to________.

A. show off her acts of kindness

B. tell us that people like being helped

C. encourage us to do acts of kindness to others

D. explain why we need to do acts of kindness

活塞未进工作筒或抽油杆断脱井口有什么现象？

缓和酸水解可用于确定（）

A.糖和糖连接顺序

B.糖的种类

C.糖和糖连接位置

D.苷键构型

E.糖的定量