【题目】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.

1According 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.

2What 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.

3The passage is mainly about ________.

A.why bacterial population growsB.how bacteria communicate with each other

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

【题目】When a Man Made Fun of His Seatmate

Soon after Savannah Phillips, a 33-year-old mother, sat down in her window seat on a United Airlines flight this past May, she glanced(瞥见)over at her seatmate. He was busy ___________. His phone was not far from her face and the letters were unusually _________, making it easy for Phillips to read the message on it: “Hey Babe, I’m sitting next to a smelly fatty.”

Tears streamed down the poor woman’s face as she tried to hide herself to the corner, trying to make herself as _________as possible.

“It awoke all the unpleasant things I think about myself. I always preferred to sit alone on flights because of my _________, fearing others next to me would feel uncomfortable. ” Phillips wrote in a Facebook post after the flight.

Sitting a row behind them was Chase Irwin, a 35-year-old bar manager. He could see Phillips crying—and then he oversaw the man’s texts.“I could not have this guy,who’s making fun of her, sit next to her this whole flight,” he said in an interview later.

_________, Irwin unlocked his seat belt and went over to the texter. “Hey, I need to talk to you,” Irwin said. “We’re switching(交换)seats—now.” When the texter asked why, he said, “You’re texting about her, and I’m not putting up with that.”

The texter quickly _________. Irwin took his place next to Phillips and was soon cheering up his new seatmate.

“He ___________me not to let that guy get to me and that everything was going to be fine,” Phillips wrote. They spent the rest of the flight chatting like friends.

With her trust in humanity restored, Phillips wrote this on Facebook: “I was so grateful(感激的)he was there. What he did set such a good_______for others to follow, that is, sticking up for people when they need help.”

1A.textingB.talkingC.playingD.working

2A.beautifulB.largeC.discouragingD.surprising

3A.warmB.braveC.smallD.light

4A.buildB.faceC.mannerD.character

5A.ProbablyB.FortunatelyC.SuccessfullyD.Immediately

6A.promisedB.remainedC.agreedD.insisted

7A.encouragedB.orderedC.warnedD.trained

8A.goalB.exampleC.taskD.time

【题目】 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。

1There 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.

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

A.2B.3C.4D.1

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

A.ItalyB.AustraliaC.JapanD.USA

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

A.Richard’sB.Sonia’sC.Wu’sD.Hannah’s

5From 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

【题目】 In order to deal with the work and pressure that seem boring, we have to take an active part in beautiful acts of love and kindness. So get to it!

1 In order to solve the problem, we must face it bravely. This can include people in your life who may be bringing you down, the environment or even a person that makes you upset and worried. It’s up to you to handle them.

In order to live a meaningful life, you must love yourself. 2 Take care of your actions and how you live each day. Love yourself fully in order to love others fully.

3 It’s not easy to make a decision about what is worth your time and effort or what is not. If situations are seriously terrible and are not repaired, it’s time to let go. Are there broken relationships or friendships but you know they are worth the time? Fix them and find peace. Do what you can to find love in situations.

4 Give our time, energy, love, and sometimes money, please. It is “The True Meaning of Life”. Everything we put into the world comes back to us. At the end of the day, no matter what you have, you are likely in a position to give something small to someone else who needs it.

Things that make us smile, laugh and feel good are just amazing. This one is pretty simple…Just do MORE of it. 5 I truly believe that in the super fast paced world we live in, happiness may not come as easily as we wish.

阅读短文,把A—E五个句子填入文中空缺处,使短文内容完整。

A.Do more of what makes you happy.

B.Take care of yourself and your needs.

C.Mend what’s broken or give it up.

D.Don’t avoid trouble.

E.Give back.

【题目】 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 () 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.

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

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

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

_____________________

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

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

_____________________

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