Music plays an important role in our lives. W...

Music plays an important role in our lives. We can hear music everywhere. We can't live _______ it. At the same time, music can ________our feelings. Different kinds of music can influence us in different ways.　　

Music makes you relax.

When you have too much ______with your study, you can listen to music for a while.

Soon you can feel relaxed. Studies show that customers would like to stay there longer when stores play relaxing music. Then they will______buy more things. So many stores try to play music that their customers enjoy.　　

Music is a healer（治愈师）.

When you feel sad, music can comfort you. Then you can feel more confident about life and your problems. When you have difficulty with sleep, some______ music can help you fall asleep easily. A group of teenagers________had depression(抑郁症）shared their favorite songs with each other. Each teenager explained why he or she liked the song. After talking about it, the teenagers said they felt__________.

Music helps you to learn.

Scientists find that you can improve your memory and intelligence______ listening to music. Don Campbell, an expert, believes music can make people,______ babies, stronger, happier, smarter and more creative. Some experts_______playing light music to help you pay attention when you are studying.　　

No matter what style of music you like, you can use it to help you.

1.A.on B.with C.without

2.A.support B.change C.keep

3.A.fun B.stress C.pleasure

4.A.possibly B.impossibly C.painfully

5.A.noisy B.loud C.soft

6.A.which B.that C.what

7.A.better B.sadder C.sicker

8.A.after B.before C.during

9.A.except B.nearly C.even

10.A.suggest B.avoid C.remain

九年级英语完型填空简单题查看答案及解析

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

九年级英语阅读单选中等难度题查看答案及解析

In our lives, friends play an important role. So we should always be there to care for _______.

A.us B.you C.them

九年级英语单选题中等难度题查看答案及解析

Everyone can play an important role in the society. As members, we should try our best to do________.

A.what we should do B.what shuuld we do

C.how we should do D.how we should do

九年级英语单选题中等难度题查看答案及解析

Friends play an important part in our lives, and although we can’t be more familiar with the fact of friendship, we often don’t clearly understand how we make friends, especially with Americans. Here are some pieces of advice on making friends with Americans:

* Visiting places Americans enjoy: parties, churches, restaurants, parks and sports clubs.

* Be willing to take the first step. Don’t wait for them to get close to you. Americans in China may not know you speak English. They may be uncomfortable if they can’t speak your language.

* Use small talks to open the conversation. Ask them where they’re from, why they come to China, etc. Remember: Be careful not to ask personal questions about age, salary and so on.

* Show an interest in their culture, their country or their job. Americans like to talk about themselves.

* Invite them to join you for dinner or just for coffee or tea. Try to set a specific （明确的）time. Americans sometimes make general invitations like “Let’s go out for a dinner sometime.” Often this is just a way to be friendly. It’s not always a real invitation.

* Don’t expect too much at first. Maybe they’re being friendly. But maybe they want to be your good friends. It will take time to tell.

1.According to the passage, Americans like to visit the following places except ______.

A．shopping centers   B．parks             C．sport clubs        D．churches

2.How many pieces of advice does the writer offer on making friends with Americans?

A．Four.             B．Five.             C．Six.              D．Seven.

3.What should you say when you meet an American for the first time?

A．What’s your age?

B．How much do you get in a month?

C．Nice to meet you! Are you from America?

D．Let’s get together sometime. I want to ask you some questions.

4.Which is the best way to make friends with an American?

A．To ask him if he is willing to make friends with you.

B．To spend a long time learning about him.

C．To wait until he tells you his thoughts.

D．To ask him to join you for dinner.

5.What do we know from the passage?

A．It’s very important to be a good friend of an American.

B．It’s difficult to get on with Americans.

C．Different peoples have different customs and cultures.

D．Friendship is the most important in our daily life.

九年级英语阅读理解中等难度题查看答案及解析

根据短文内容及首字母提示完成短文。（每空一词）

Friends play an important part in our lives. We may have many friends, but we often don't understand c71 how we make friends. We may get on well with a n72  of people, but we usually make friends with a very few of them.

People use the word "friend" freely. Friends may k73 each other since childhood or they may recently meet. In fact, people many have different k74 of friends such as school friends, work friends, or sports friends. A person may c75different friends for different activities. If you play with s76  on the playground, the person is your playmate. If you often play chess w77   a friend, the person is your chess partner.

One may have many good friends and only one best friend. " Best friends" or "close friends" are u78 two people who have known each other for a long time. A close friend is someone who is able to s79  experience, joys and sorrows(悲伤) with you. This is a person you can rely on (信赖) when you are in n80 , and this is the person to whom you are willing to lend a helping hand.

Friendship is one of life's greatest treasure.

九年级英语单词拼写困难题查看答案及解析

短文首字母填空：根据短文内容及首字母提示，填写所缺单词（10分）

Friends play an important part in our lives. We may have many friends, but we often don’t understand c  1 ________how we make friends. We may get on well with a

n  2  of people, but we usually make friends with a very few of them.

People use the word “friend” freely. Friends may have k  3__ each other since childhood or they may have recently met. In fact, people may have different k  4__  of friends such as school friends, work friends, or sports friends. A person may

c  5 different friends for different activities. If you play with s  6  on the playground, the person is your playmate. If you often play chess w  7  a friend, the person is your chess partner.

One may have many good friends and only one best friend. “Best friends” or “close friends” are u  8  two people who have known each other for a long time. A close friend is someone who is able to s   9  experiences, joys and sorrows with you. This is a person you can rely on（信赖）when you are in n  10 , and this is the person to whom you are willing to lend a helping hand.

Friendship is one of life’s greatest treasures.

九年级英语其他题中等难度题查看答案及解析

Everyone can play an important part in society. As members, we should try our best to do __　　　 .

A. how we should do　　　　　　　　　　　　　　 B. what should we do

C what we should do　　　　　　　　　　　　　　　　 D. how should we do

九年级英语单项填空困难题查看答案及解析

Smart phones play an important role now. As long as we take them，we can ______ many problems easily.

A.deal with B.stick to C.cut off

九年级英语单选题中等难度题查看答案及解析

Stamps help connect us with others. They have played an important role in people's lives for a long time.

Stamps pay for a letter to get where it needs to be. When there were no stamps, people did not pay for the letters they sent, but instead they paid for the letters they received. The first stamp ever made is called Penny Black. It is a British stamp made in 1840 with a picture of Queen Victoria on it. The number of people who send letters and use stamps has gone down. But stamp collection is still one of the world' s most popular hobbies. There are even stamp clubs to help people find new stamps to add to their collections. Interestingly enough, the Internet may have reduced the need for stamps, but it is actually helping collectors find more stamps to add to their collections.

任务5: 根据短文（C）内容完成表格,每空一词

九年级英语填空中等难度题查看答案及解析