题目内容

她把牛奶收好后转过身来。

She finished ________ the milk ________ and turned around.

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Bacterial Quorum Sensing

Bacteria(细菌)play an important role in our lives. They can keep us alive as well as make us sick. It wasn’t until fairly recently that we learned bacteria can communicate with one another.

In the 1960s, researchers found that a kind of bacteria called Vibrio fischeri（费氏弧菌） produced no light when they were alone, but that they exhibited great amount of light as the bacterial population grew to a certain number. How did this happen? How can Vibrio fischeri tell the difference between times when they’re alone and times when they’re in a community, and then all do something together?

Researchers found they talk to each other with a chemical language—signal molecules(信号分子). Vibrio fischeri makes signal molecules, and it also has a receptor on its surface that fits like a lock and key with a signal molecule. As the bacteria increase, more and more signal molecules are sent into the environment. When signal molecules increase to a certain amount, they lock down into those receptors and information comes into the bacteria, which tells them how many neighbors there are. As soon as they realize the population has hit the certain number, all of the bacteria behave as a group, making light together. In the past ten years, researchers have found all bacteria have systems like this: they make and recognize chemical words, determine(判断)the size of the community, and carry out tasks that would be unsuccessful if a single one were to act alone. This process is called quorum sensing.

Most of the time, bacteria live with thousands of other species (种类)of bacteria. There has to be a language of interspecies communication. In fact, bacteria have another kind of signal molecule, which is the common language used by all species. Moreover, this kind of molecule has its own receptor. In this way, bacteria are able to count different populations, and then they decide what task to carry out depending on which species has the greatest population.

Knowing how bacteria communicate could influence how we fight disease. What if bacteria can’t talk or hear? They won’t recognize when there are enough bacteria and when to exhibit the group behavior to make us sick. Researchers are developing a method—to make molecules that look like the real ones and then they lock into the receptors to jam recognition of the real situation.

On the other hand, researchers also improve the conversation of the beneficial bacteria, so they can do things that we want them to do better than they would do on their own.

1.According to the passage, what can we learn about quorum sensing?

A.Quorum sensing may happen when there is only one Vibrio fischeri.

B.Signal molecules are kept away from receptors during quorum sensing.

C.Most bacteria have similar systems to make light during quorum sensing.

D.Bacteria carry out a group task when their population hit a certain number.

2.What can we learn from the passage?

A.The more species there are, the more group actions bacteria will take.

B.In different environments, bacteria have different interspecies languages.

C.Beneficial bacteria communicate better by themselves than harmful ones.

D.To fight disease, researchers try to turn off the communication between harmful bacteria.

3.The passage is mainly about ________.

A.why bacterial population grows B.how bacteria communicate with each other

C.which bacteria help fight disease D.what scientists do to find quorum sensing

We spend hours, days and years of our lives in school. Imagine you could design（设计）your dream school, what would it be like? What would you be doing? We wanted to find out what teenagers around the world thought.

Here is what they said:

Richard from the USA: My dream school would have a big swimming pool. It would also have a cinema, a gym and a shopping center. My school has none of these and I think there should be more pleasant things for students to do while they are studying.

Sonia from Italy: I’d like a room where we can relax and play computer games. I’d also like to have a music room. I think there should be a place for everyone to go and relax after class.

Wu from Beijing: I think it would be great to have another day off every week, besides the weekend. If that day was a Friday or a Monday, we would have a long weekend every week. What fun! I also think school should start later, at about 10 o’clock, and finish earlier.

Hannah from Australia: In my dream school, I think the teachers should give us more freedom and choice about how we study and what we study. I also think it’s not necessary for us to wear school uniforms every day. I really don’t like wearing it.

根据材料内容，选择最佳答案。

1.There would be __________ in Richard’s dream school.

A.a big swimming poor and a music room

B.a room to relax and play computer games

C.a long weekend, three days off every week

D.a big swimming pool, a cinema, a gym and a shopping center.

2.Wu wants to have ____________ days off in a week.

A.2 B.3 C.4 D.1

3.The country of ___________ is NOT mentioned in the passage.

A.Italy B.Australia C.Japan D.USA

4.In ___________ dream school, the teachers should give them more freedom and choice for study.

A.Richard’s B.Sonia’s C.Wu’s D.Hannah’s

5.From the passage, we know that __________

A.Sonia from Italy would like a room where she can relax and play computer games

B.Richard from the USA think his dream school should start at 10 o’clock

C.Wu from Beijing thinks it would be great to have two days off every week

D.Hannah from Australia likes wearing a school uniform every day

The little girl has a high _____________, she should be sent to hospital right away.

New rules and behavior standards (行为规范) for middle school students came out. Who are the most excellent students? Middle schools use a new way to decide that. The best students won't only have good grades. They will also be the kids who don't dye (染) their hair, smoke or drink. The following are some of the new rules.

Tell the truth. Have you ever copied others' work during an exam? Don't do it again. That's not what an honest student should do. If you played computer games for two hours in your room, don't tell your parents you were doing your homework.

Do more at school. Good students love animals and care about others. April is Bird-Loving Month in China. Is your school doing anything to celebrate it? You should join! That way, you can learn more about animals and learn how to protect them. And when your classmates are in trouble, remember to give them a hand. A friend in need is a friend indeed.

Use the Internet carefully. Try to keep away from web pages that are bad for you. Find good websites and use them for homework.

Be open to new ideas. Have you ever thought that people could live on the moon? Maybe you can discover a new planet someday. Don't look down on new ideas. You should welcome them because new ideas can make life better.

1.Middle schools use a new way to decide ________ the most excellent students are.

2.It's not honest to __________others' work during an exam.

3.Which sentence means"患难见真情"in the third paragraph?

_____________________

4.New ideas can make your life better, so ____________________.

5.How many rules are mentioned to be the most excellent students?

_____________________

There is always something unexpected in our life. I find it humorous sometimes that even the most ordinary thing can have an _______ on us.

My wife, daughter, and I moved into our home nine years ago and we _______ a lot of time and energy working in the yard to get it look like what it does today. We called this area our "rock garden" because there were so many rocks. We did the best we could to make the yard _______. Then, we started to grow plants and flowers and _______ them carefully.

Last summer I walked to the end of the rock garden and found a tiny little plant that I could not immediately tell what it was. I knew I didn't plant it and Denise said that she didn't _______. We decided to let it continue growing until we could _______ what it was.

Weeks passed and as I made my way back to the mystery (神秘的) plant, I found it grow taller. It appeared to be a Sunflower. As I pulled rocks from the area, I noticed something _______. The Sunflower didn't start where I saw the stalk (茎) begin. It actually began under a big rock and grew under and around it to _______ the sun.

Suddenly I realized something. "_______ a tiny little Sunflower has the ability of overcoming a big rock standing in its way of developing, we also have the ability of doing the same thing. "Like the Sunflower, it knew it had the ability to overcome difficulties.

Stand tall like the Sunflower and take ________in who and what you are and the environment will begin to support you. You will find a way to go under or around big difficulties in order to achieve your goal.

1.A.idea B.opinion C.experience D.influence

2.A.spent B.paid C.took D.cost

3.A.unclean B.tidy C.messy D.dirty

4.A.looked for B.looked after C.looked through D.looked over

5.A.too B.also C.either D.so

6.A.find out B.look out C.put out D.try out

7.A.interesting B.enjoyable C.ordinary D.unusual

8.A.hold B.reach C.catch D.have

9.A.Because B.Although C.If D.But

10.A.praise B.pride C.attention D.advice

There was a heavy traffic. ________, I was late for the meeting.

A.As a result B.At first C.As well as D.For example

—We lost the match.

—________. Better luck next time.

A.Hope things work out B.Have a good day C.Never mind

Is it possible for animals to raise a human child? There are many stories that suggest it is possible. Not just wolves and dogs, but also sheep, bears and even monkeys are able to look after human children, Daily Mail reported.

There is the case of Ivan Mishukov, a 6-year-old boy from Moscow. Police found him living with dogs in the city's streets in 1998. There, he had been begging for two years. Ivan found food to feed the dogs. And in return, the dogs kept him warm and protected him while he slept. When he was saved, he could hardly speak. Luckily, he later joined the army and lived like a normal adult.

But not all children who are raised by animals can adapt to human society. In 1848, British soldier Colonel William Sleeman found a little boy living with many wolves in India. He took him to a village, taking care of him and trying to teach him to speak. But nothing worked. The boy still behaved like a wolf, eating raw (生的) meat and refusing to wear clothes, no matter how cold the weather was. About two years later, he got very sick and passed away.

Some animals are believed to have strong maternal instincts (母性本能), which guide them to care for young animals, even those of other species(物种). However, people need to know that children raised by animals may experience long-term negative effects when they enter human society, according to Daily Mail.

根据短文内容，选择最佳答案。

1.Ivan Mishukov was raised by________.

A.wolves B.monkeys C.dogs D.bears

2.What could the dogs do for Ivan?

A.They begged food for him. B.They warmed him.

C.They talked with him. D.They took him to join the army.

3.The case of the boy raised by wolves shows us that children raised by animals________.

A.can learn from animals B.can live longer

C.can speak animal language D.may harm human beings

4.What did the Daily Mail say?

A.Animals can take good care of human babies.

B.Some animals have strong maternal instincts.

C.Some animals can't tell themselves apart from other species.

D.Children raised by animals are stronger than other people.

5.Where might you find this passage?

A.A fashion magazine. B.A science-fiction novel.

C.A sports article. D.A science magazine.

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