A new study finds that plants communicate with one another to warn of danger.
We often consider plants as the furniture of the natural world. They don’t move; they don’t make sounds；they don’t seem to act on anything. But as is often the case, plants talk to each other all the time. And the language is a chemical (化学物质).
Over the years, scientists have reported that different types of plants, from trees to tomatoes, give out chemicals into the air to help neighbouring plants. These chemical warnings can spread information about one plant’s disease or infestation (虫害)，so other plants can protect themselves. But how plants receive and act on the information exactly is still mysterious (神秘的）.
In this week’s Science Magazine, researchers in Japan offered some explanations. They have found out one chemical message and traced it all the way from beginning to end.
The scientists looked at tomato plants infested by a common pest (害虫）. To start out，they grew plants in two separate plastic spaces connected by a tube (管子）. One plant was infested and placed upwind and the other was uninfested and placed downwind. The downwind plants were later exposed (暴露的）to the pest. The results showed that plants near sick neighbours before were able to protect themselves better against the pest.
They found one chemical appeared more often in the exposed plants. The chemical is called HexVic. The scientists discovered where HexVic came from, and put it over healthy plants. Those plants were then able to produce HexVic. Researchers made sure that uninfested plants could fight off bugs and diseases. How do they know when to protect themselves? They are warned first by their friendly plant neighbours.
It is not a simple story , and it may be happening in many other plants besides tomatoes. It may also be happening with more chemical signals that are still unknown to us. In a word, we know that plants not only communicate, but also look out for one another.The underlined word “traced” in the fourth paragraph probably means _______here.
| A．reported | B．followed | C．doubted | D．developed |
For scientists, which are the right steps to watch tomato plants infested by a pest?
① Place the infested plant upwind.
② Place the uninfested plant downwind.
③ Expose the downwind plants to the pest.
④ Grow plants in two separate plastic spaces connected by a tube.
| A．③①②④ | B．①④③② |
| C．④①②③ | D．④②①③ |
You can put the sentence “The researchers also studied leaves from exposed plants and unexposed plants. " at the beginning of Paragraph ____.
| A．3 | B．4 | C．5 | D．6 |
Which of the following can be the best title of this passage?
| A．Communicating Plants and Terrible Diseases |
| B．Talking Plants and Friendly Warnings |
| C．Protecting Plants and Clear Information |
| D． Growing Plants and Mysterious Chemicals |
Five years ago, I met her in a shopping center. I was walking through the shop when I saw her. Then she came back to my house with me. After that, we became friends.
Once she had to go into hospital to have an operation(手术) on her leg. I was worried about her and looked after her every day. I made breakfast for her. I was not good at cooking, but she never complained. I also helped her take showers.
I have no idea why we can be good friends, because she is quite different from me. I like writing, reading and playing computer games. But she loves outdoor activities. She likes playing balls best. She also loves sleeping.
She will run all around the house to lick(舔) my face if someone shouts “Kiss for Dad.” That is the only name she knows me by—Dad, though I call her by many names—Pickle, Missile and Little. But her real name is Pixar. This week she turns seven years old.Where did the writer met Pixar?
| A．On the street. | B．In a hospital. |
| C．In a shopping center. | D．In an animal center. |
Pixar was years old when the writer met her.
| A．two | B．five | C．seven | D．one |
What can we learn from the passage?
| A．Pixar once had an operation on her head. |
| B．Pixar doesn’t like playing outside. |
| C．Pixar is the writer’s dog. |
| D．Pixar calls the writer “Dad” every day. |
What’s the best title for the passage?
| A．How to Make Friends | B．My Good Friend |
| C．Strange experience. | D．How to Be a Good Friend |
If you go into the forest with friends, stay with them .If you don’t, you may get lost. If you do get lost, this is what you should do. Sit down and stay where you are. Don’t try to find your friends. Let them find you. You can help them to find you by stay in one place.
There is another way to help your friends or other people to find you. Give them a signal(信号)outing or whistling (吹口哨) three times. Stop. Then shout or whistle three times again. Any signal given three times is a call for help.
Keep on shouting or whistling, always three times together. When people hear you, they will give two shouts or two whistles. When a signal is given twice, it is an answer to a call for help.
If you don’t think that you will get help before night comes, try to make a small room with branches.（树枝）
What should you do if you get hungry or need drinking water? You would have to leave your little branch room to look for something to eat and drink. Don’t just walk far away. Pick up small branches and drop them as you walk so that you can find your way back.
The most important thing you need to do when you are lost ---stay in one place.When you hear two shouts or whistles, what does that mean?
| A．Some animals are coming. |
| B．Someone is calling for help. |
| C．People will come to help you |
| D．Someone is lost. |
What shouldn’t you do, if you get lost in the forest?
| A．Walk everywhere to find your friends. |
| B．Sit down and stay where you are. |
| C．Make a small room with branches. |
| D．Try to find something to eat and drink |
Which of the following is wrong according to the passage?
| A．You can leave your branch room to find some food. |
| B．You can’t go anywhere even when you feel thirsty or hungry. |
| C．You should leave some branches as you walk. |
| D．Don’t go far away from your room. |
There are many clubs in our school. My English is not good. I want to join the English club. Wang Ying wants to learn to paint. So he wants to join the art club. Zhang Ping likes running. He wants to join the running club. Li Nan is good at singing and she wants to join the music club. What club does Han Mei join? Oh, she likes eating and she joins the cooking（烹饪）club.My _______ is not good.
| A．Chinese | B．English | C．Maths | D．Art |
What club does Wang Ying want to join?
| A．The music club. | B．The sports club. |
| C．The art club. | D．The swimming club. |
Who wants to join the running club?
| A．Zhang Ping. | B．I. | C．Wang Ying. | D．Li Nan. |
Li Nan _______ very well.
| A．dances | B．paints | C．sings | D．plays tennis |
Why does Han Mei want to join the cooking club?
| A．She likes cooking. | B．She likes eating. |
| C．She can cook. | D．She wants to be a cook. |
Mr Brown lives on Green Street now. He wants to send a postcard(寄贺卡)to his pen pal in Toronto,but he doesn’t know where the post office is.“Which is the way to the post office?”he asks his new neighbor Joe. “I want to send a postcard to Toronto.”“The post office is quite far from here,” answers Joe. “If you only want to post some letters or post cards ,you needn’t go to the post office. You can put them into a mailbox down the street Where does Mr Brown live now?
| A．He lives on Center Street. |
| B．He lives in Toronto. |
| C．He lives on Green Street. |
| D．He lives in a post office. |
Where does Mr Brown want to go?
| A．A pen pal’s house. | B．A mailbox. |
| C．A post office | D．Toronto. |
What does Mr Brown want to do in the post office?
| A．He wants to go to the mailbox. |
| B．He wants to buy some stamps. |
| C．He wants to send a postcard. |
| D．He wants to know the way to Toronto. |
Where is the post office?
| A．On Green Street. | B．In Toronto. |
| C．We don’t know. | D．In the neighborhood. |
Where can Mr Brown post the postcard in the neighborhood?
| A．The post office. |
| B．The mailbox in the post office. |
| C．The mailbox on the street. |
| D．His house. |
Did you know that you can help the environment if you buy recyclable products instead of non-recyclable ones? Look for the recycle s —— three arrows that make a circle – on the package. Recyclable products are usually made out of things that already have been u
. It usually takes less energy to make recycled products than to make new ones. The more energy we save, the b
.
Imagine that it's a hot summer day. You put an ice cream on the sidewalk, and it melts. W does this happen? Well, you probably know that the sun causes the ice cream to melt. But you may not know that the sun produces solar energy. Solar energy is a
way of saying "energy that comes from the sun." Solar energy can be used to heat homes, buildings, water, a
__ make electricity. Today, more than 200,000 houses in the United States make use of the s
energy.
Cars are an important part of life for most people. But cars also cause pollution and give out a lot of greenhouse gases into the air. L , there are some cars that are better for the environment. These cars can travel longer on a smaller amount of gasoline. They don't p
much, either. Using these kinds of cars can help reduce the amount of greenhouse gases in the air.
Many things, l computers, TVs, stereos, and VCRs, have special labels on them. The label says "Energy" and has a picture of a star. Products with the ENERGY STAR® label are made to save energy. Buying products with ENERGY STAR® labels will help protect the environment.