溶菌酶杀菌的作用机理是（） A.裂解聚糖骨架的β-1，4糖苷键 B.竞争肽聚糖合成中

A 5R Rule for Environment

1. Reduce(减少)

If you want to reduce waste, you should use things wisely. A large number of trees are being cut down to make paper. If everyone uses a little paper carelessly and throw it out, soon we would not have any trees left. Other things are also being wasted, and people don’t know what to do with the waste in big cities. So it is necessary to reduce the waste.

2. Reuse（再利用）

You should always think of reusing the usable things before throwing them out. Give your clothes you do not use or the ones which are too small to the poor. In a family, you may pass on such clothes to younger brothers or sisters.

3. Recycle（回收）

Bottles, cans and paper can easily be recycled. By doing so we save lots of time and money. For example, coke cans are sent to a factory, where they are smashed(打碎) flat and melted(融化) and the metal things are made for new coke cans.

4. Recover （恢复）

When you buy a box of apples, there may be a few rotten apples, you have two choices: one is to throw the whole apples away, or you could cut off the rotten parts and use the good parts. In this way, you are recovering the eatable parts of food.

5. Repair（修补）

If one of the legs of your table is broken, you can repair it. If you want to change for better ones, it is better for you to sell the old things or give them to other people who can use them after doing some repair. It is true that North America is a “throw—away” society, but the time has come to change our way of life so that we can protect our environment. Every one of us should try our best.

小题1:The “Reduce” rule mainly requires(要求) us ______.

A. to use things wisely

B. to cut down many trees

C. to use less paper

小题2: The right order of recycling coke cans is ______.

a. collect the used cans   b. melt them    c. smash them flat   d. send them to a factory

A. a b c d             B. a d c b         C. d b c a

小题3:The “Recover” rule mainly requires us ______.

A. to throw waste thing away

B. to cover waste thing with the earth

C. to get back the useful parts

小题4: ______ is the best way to do with your broken tables.

A. Throwing them away   B. Repairing them       C. Putting them away

小题5: According to the passage, ______ can not be reused.

A. clothes             B. shoes           C. rotten apples

按工作原理划分，汽轮机可以称为（）汽轮机。

A.抽气式

B.轴流式

C.凝汽式

D.冲动式

阅读理解.

     It feels like every time my mother and I start to have a conversation,it turns into an

argument.We talk about something as simple as dinner plans and suddenly,my mother

will push the conversation into World War ?.She'll talk about my lack of a bright future

because I don't plan to be a doctor.And much to her disappointment,I don't want to do

any job related to science,either.In fact,when I was pushed to say that I planned to major

(主修) in English and communications,she nearly had a heart attack.

     "Why can't you be like my coworker's son?" she bemoans all the time.Her coworker's

son received a fouryear scholarship and is now earning 70,000 dollars a year as an engineer.

I don't know what to answer except that I simply can't be like Mr Perfect as I've called the

unnamed coworker's son.I can't be like him.I'm the type of person who loves to help out in

the community,write until the sun goes down,and most of all,wants to achieve a career

because I love it,not because of fame (名声) or salary.

     I understand why my mother is worried about my future major.I've seen my mother

struggle to raise me on her small salary and work long hours.She leaves the house around

6﹕30 am and usually comes home around 5 pm or even 6 pm.However,I want her to

know that by becoming a doctor,it doesn't mean I'll be successful.I'd rather follow my

dreams and create my own future.

1. Which of the following topics do the writer and his mother often talk about?

A．The writer's studies.

B．The writer's future job.

C．Dinner plans.

D．Wars around the world.

2．We can infer from Paragraph 1 that the writer's mother________.

A．doesn't want the writer to major in English

B．doesn't think the writer should be a doctor

C．gets along very well with the writer

D．doesn't think working in the science field is a good idea

3．The underlined word "bemoans" in Paragraph 2 most probably means "________"．

A．agrees

B．shouts

C．complains

D．smiles

4．Which of the following statements is probably TRUE about the writer?______.

A．He wants to be like his mother's coworker's son.

B．He wants to find a job in his community in the future.

C．He doesn't think his mother's coworker's son is perfect.

D．He wants to do something he really likes in the future.

5．We can know from the last paragraph that________.

A．the writer doesn't know what his future will be like

B．the writer's mother works very hard for the family

C．the writer doesn't think being a doctor is a good job

D．the writer sometimes thinks his mother's advice is very good

如图的弯曲杠杆A端吊一重物G．要想在B端加一最小的力F，使AO保持水平平衡．试画出此力的方向和力臂．

下面选项中，不属于问卷的组成部分的是（）。

A.前言

B.主体内容

C.结束语

D.序言