Squirrels(松鼠),asanimals loved by many people, are getting ready for winter. They are looking for nuts(坚果), digging(挖) holes in the ground or finding holes in trees. They keep the food they will need during the coming months there, when the weather is cold and sometimes snowy.

Squirrels spend a lot of time in trees which are like restaurants for them. Among their favorite things to eat are nuts and other parts of trees. Squirrels may also eat other animals. And anyone who has a bird knows squirrels love bird food!

Squirrels stay active all winter, so they need plenty of food to help keep their energy. Squirrelstend to bury(埋) food underground, piece by piece. Some squirrels may collect food together and bury underground.

When they need the food in the winter, squirrels use their memories and sense of smell to help them find what they buried. Sometimes, you’ll even see them digging through the snow just to find food.

Squirrels build home in trees. Some squirrels spend much of the winter in underground holes which are warmer.

When spring comes, squirrels change their eating habits to new plant growth. Sometimes they forget to dig up all their buried nuts. That’s why you’ll sometimes find a little tree growing in a place you know, but neither you nor your family planted it. It must have been the squirrels.

Do you often throw away things you don’t need anymore? Have you ever thought about how these things can actually be put to good use? Nothing is a waste if you have a creative mind.

You have probably never heard of Amy Hayes, but she is a most unusual woman. She lives in a house in the UK that she built herself out of rubbish. The windows and doors come from old buildings around her town that were pulled down. The top of the house is an old boat turned upside down. And the gate in front of her house is made of rocks and old glass bottles. Amy recently won a prize from the Help Save Our Planet Society. The president said, “ Amy is aninspirationto us all.”

Amy isn’t the only one who is good at recycling. Jessica Wong fromHong Konguses old clothes that people don’t wear anymore to make bags. She has been doing this for a few years now. She opened a small shop where she sells her bags, and she has also set up a website to sell them online. She especially likes to use old jeans to make handbags. Her bags are cute and useful. “I plan to write a book about new ways to use old clothes,” she said. “ I hope people can read my book and enjoy it.”

Wang Tao set up a small business in Shanghai four years ago. He is known for using iron and other materials from old cars to make beautiful art pieces. Some are large pieces that look like animals or humans, and some are smaller pieces you can put at home. The more popular works can even be seen in art shops around the city. Wang Tao hopes to set up a “metal art” theme park to show people the importance of environmental protection. Not only can the art bring happiness to others, but it also shows that even cold, hard iron can be brought back to life with a little creativity.

You have often looked into a mirror, of course. But you haven't seen the real picture of your face yet. And why couldn't you see it? When you look into a mirror, you don't see your face as other people see it. You see a reversed picture. If you close your left eye, your picture closes its right eye. If you touch your right ear with your right hand, your picture touches its left ear with its left hand.

   If you have two small mirrors, you can see your faces as your friends see it. You hold the two mirrors at right angles (角度) to each other and look into them. After some practice you will be able to see the real picture of your face.

   Now close your left eye and your picture closes its left eye too. Touch your right ear with your right hand and your picture touches it s right ear with its right hand! This happens because each mirror reflected (反射) the picture in the other mirror. So you see a reversed picture of a reversed picture, which, of course, is the same as the real picture.

                            Warm air needs more room

As its temperature rises, air starts to act a little differently. Find out what happens to a balloon(气球) when the air inside it heats up with this fun science experiment for kids.

What you will need.

●An empty bottle

● A balloon

● A pot of hot water (not boiling)

Instructions

What is happening?

As the air inside the balloon heats up, it starts to expand. The molecules(分子) begin to move faster and further apart form each other. This is what makes the balloon stretch. There is still the same amount of air inside the balloon and the bottle. It has just expanded as it heats up. Warm air therefore takes up more space than the same amount of cold air. It also weighs less than cold air occupying (占据) the same space. You might have seen this principle(原理) in action if you’ve flown in or watched a hot air balloon.

Choose the right answer according to the passage.

Do you know 3-D printing? It is very new and is developing fast all over the world. With its help, people can print real world things with a 3-D printer. People believe it will have a very great future. 3-D printers seem to be able to make many things in just a short time.

   However, 3-D printing is still a little expensive for everyday use, but we believe we will have personal 3-D printers in the near future.

   Many people are dreaming even bigger, and it seems that if you can imagine it, you can 3-D print it. If not now, then will be soon. Look, some people already have exciting imaginations!

Some toy companies are working on helping kids imagine their toys and then printing them. And there are already 3-D printed candies! A company inChinaeven built 10 houses in Shanghai in one day with a large 3-D printer. Are they the most comfortable homes? No. But they could help the homeless people a lot. These houses didn’t cost much (each house cost about $5,000). It’s a cheap and very environmentally (环保的) friendly way to build houses.

   North American black bears are shy animals. They are fearful by nature, and will usually run away if they see or hear people. Because of this, it can be difficult for scientists to learn about these animals.

   In order to study black bears, researchers from New Jersey, USA, catch bears and use drugs to help them go to sleep. Researchers then work out the size and the weight of the bear, take blood to test for diseases, remove a tooth and take it to the lab to find out its age. From these studies, researchers want to find out how many bears live in New Jersey, how long they live, and how many babies they produce.

   But in Minnesota, USA, researchers study bears that are completely awake. The bears know the researchers' voices and they aren't afraid of the research team. With the help of a few grapes to keep the bears busy, researchers can touch them to check their hearts, look at their teeth, and do other jobs. Researchers can also walk or sit with bears for hours and make videos to learn about their everyday lives.

   In both places, the main purpose is the same--to make sure there is a healthy population of black bears. But the research ways and the kinds of information that researchers are able to collect are quite different.

Taking away a city's rubbish is a big job. Every day trucks come into a city to collect them. Most rubbish is made up of things we can't eat or use. If we keep these things, we would soon have a mountain of rubbish.

   In some cities the rubbish is collected and taken outside the city to a dump (垃圾场). Often the city dump is placed where the ground is low or where there is a big hole. The kitchen rubbish is broken into small pieces and sent into the sewage system. The sewage system takes away the used water from toilets, bathtubs and other places.

   To keep mice and flies (苍蝇) away, some earth is used to cover the newly dumped rubbish. Later, grass may be planted on the rubbish -filled land. Finally, a house or a school may be built there, and then you'd never know that this had once been an old rubbish dump.

   In other cities rubbish is burnt in special places. The fire bums everything but the metal. Sometimes the metal can be used again in factories where things are made of metal. The food parts of rubbish are put in special piles (堆) where they slowly change into something called humus (腐蚀质), which looks like black earth. It is rich with the kinds of things that feed plants and help them grow.

根据材料内容,选择最佳答案,并将其标号填入题前括号内。

Robots are smart. They can help people do some difficult jobs. Some robots do everyday jobs. People use them in many ways. They are different from people and they never get tired and don’t need sleep. And they can do dangerous and dirty jobs. They also do the job nicely again and again.

      People use robots in space, too. It is much cheaper to send an unmanned spacecraft into space than to send a manned one. In space, robots can take photos of things in space, do experiments, send the information back to the earth.

      Robots are also useful in hospital. Now with the improvement of science, doctors only need to make a small hole(洞) when they operate（做手术） on a sick person. A tiny robot can be put into the person’s body. Then doctors can watch what it is doing on a computer. The robot deep inside the body listens to the instructions and do as the doctors says.

After a long day’s study at school, you are very tired. So after school you go home to relax. When you get home, a robot greets you. He’s happy to see you and helps you take your school things to your room. He listens to you talk about your school life and tells you a new joke. And he tells you to call your cousin and to say happy birthday. And then he helps you with your homework.

This is your future, and the robot’s name isNAO. NAO has a small body, big eyes and a large head. He can walk and dance. He listens and talks, and he even learns and thinks for himself. His creators (创造者) predict that the robot will be in people’s homes before 2040.

This $16,000 robot knows who you are. NAO can even express emotions (表达情感). He is a self-guided robot. A self-guided robot can sense (感觉), think and act. For example, a robot might sense things using cameras and think using computers, but with no arms, he can’t act. Another robot can move and sense things, but he can’t think for himself. These aren’t self-guided robots. But NAO can do them all. 

It was a nice day. Mrs Smith took all her children to the park. She told them not to go anywhere by themselves. All of them said they wouldn’t.

On the way Alan said, “I want a lolly (棒棒糖), Mummy.”

“You all can have a lolly in the park if you follow the rule (遵守规则).”

When they got to the park, Mrs Smith sat under a big tree. The children ran off to play. In ten minutes, when Mrs Smith looked up, she saw Alan, Shona and Fiona, but didn’t see Jack anywhere. “Fiona, where’s Jack?”

“I don’t know, Mummy. He’s not here.” Mrs Smith asked Alan and Shona. They didn’t know, either.

They walked around the park looking for Jack. At last they found him near the lolly man.

“Jack, what are you doing here? Now we have to go home because you don’t follow the rule.”

“But, Mummy, I want a lolly.”

“You can’t have one today, Jack.” Mrs Smith bought lollies for the three other children. When they got home, she talked to Jack. “Mummy has many children, Jack. To keep you safe, we have to follow rules.” Jack was sorry. He never broke rules again.

根据材料内容选择最佳答案。