With the development of technology, WiFi is becoming more and more popular and important in people’s daily life.But have you ever experienced it? Just imagine what life will be like if there is no Internet.Maybe you won’t be able to talk with friends, play video games or search for information for your homework on the Internet.But in fact,only one third of the world’s population are able to get information on the Internet.The rest are too poor to buy WiFi access(使用    权) or they live in remote areas.As a result, they live without the Internet.

  Google and Facebook, two world-famous technology companies, have decided to do something about it.Google’s Project Loon will try to send balloons which are 15 meters wide into our Earth’s stratosphere(平流层) in 2015.The balloons are made of a special material that is three times thicker than the plastic bag we use every day.Each balloon will carry a minicomputer and a WiFi radio.The WiFi radio will send the Internet over the areas it is floating over.Then people can get up-to-date information on weather or news.

On the night of the Mid-Autumn Festival in 2016, Tiangong-2, China’s second space lab (空间实验室) flew to the sky. It flies around the Earth and will run for at least two years.

On October 17th, the Shenzhou 11 manned spacecraft (载人飞船) sent two astronauts to the lab. They worked in the lab for thirty days. They did important experiments(实验) in physics and medicine.

On November 20th, the two astronauts appeared in the TV show Challenge(挑战) the impossible. They gave us a wonderful show from the space lab Tiangong-2.They successfully challenged what seemed impossible in space. Before the game, Chen Dong and Jing Haipeng, an astronaut on his third space trip, showed the bat they were given to play pingpong in space. Then the astronaut Chen Dong sent a ball on one side, ran after it to the other side to catch up with it, then beat it back. He did like this many times. According to an expert, playing pingpong in space is really impossible. In space, when the ball is hit, it goes only straight forward and cannot spin(旋转) in the air. But Chen Dong made it. After that, they showed us some young plants of lettuce (a kind of vegetable)and rice that they grow in space. This is the first time the Chinese plant vegetables in space. At last, Chen Dong stood on his head to drink some pu-erh tea. He finished this special challenge successfully.

After the space lab task comes to an end, China will start building our own space station. The plan is to have the first space station working around 2022.

         Many people may think that animals in the zoo are happy, but they are not. Do you know why? Animals like tigers and lions usually live in forests (森林). They run (跑) and play with their children and catch (捕捉) small animals for food. But now they live at their small homes in the zoo. Every day they just see many people come to visit the zoo. And they don’t have to find food. The zookeepercan give them food. They just eat, and sleep (睡) every day. Their life (生活) in the zoo is quite different from that in the forest. Why? They are not free!

We all want to protect our environment, but most of us are too busy or too lazy to do that.

Here are some tips for improving our environment.

  Use compact fluorescent light bulbs(节能灯).It is true that these bulbs are more expensive,but they can be used for longer time and they can save energy, and in the long term you will spend less money.

  Give away.You have lots of clothes or things you want to throw away. If ther are still usable,give them to someone who needs them. You can also choose to give them to charities.

  Turn off your devices.When you do not use a device , turn it off. For example,if you don’t watch TV,turn it off. Turn off the light when you leave the room. It’s an easy habit to keep and you can save energy and a lot of money.

  Walk or bicycle.Driving is one of the biggest causes of pollution. Walk or ride your bike if the journey is a short one.

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.

Have you ever thought of why dogs are human's best friends? What's the bond (紧密关系) between human and dogs? A new study by Japanese scientist Miho Nagasawa seems to have found the answer, and it has to do with something named the cuddle (拥抱) chemical.   

The cuddle chemical has another, more scientific name: oxytocin (催产素). Oxytocin is something in the blood that encourages bonding. Levels of oxytocin increase, for example, when a mother feeds her newborn baby. According to Nagasawa's study, levels of oxytocin can also go up when we look deeply into the eyes of a dog.   

Humans and dogs have been working together for nearly 3000 years. In order to better understand how the cuddle chemical worked between dogs and humans, Nagasawa and his team did an experiment. Then tested levels of oxytocin in dogs and humans, and then put them in a room to interact (交流) with each other. Then the scientists tested their levels of oxytocin again.

The researchers found that levels of oxytocin were higher in both humans and dogs after they interacted. However, levels were the highest in the humans and dogs that simply looked into each other's eyes, without much petting or talking. The longer the humans looked into the eyes of the dogs, the more cuddle chemical was let out. Nagasawa did the same experiment with wolves, but it did not give the same results.

                            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.

What were the coolest inventions made in 2015? Time magazine's 25 "Best Inventions of the Year" might give you an idea.  Cool inventions change our lives in many ways. Here we picked a few of them for you to learn about.

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.

Jenny was a five-year-old girl. One day, while she was shopping with her mother, she saw a plastic pearl necklace (塑料珍珠项链) and loved it so much. So she asked her mother to buy it for her.

 Every night, before Jenny went to bed, her dad would read stories to her. One night, when he finished the story, he asked, “Jenny, do you love me?”

“Dad, you know I love you,” Jenny answered.

“Well, give me your necklace,” Dad said.

“No, Dad. But you can have my favorite doll.”

 Several times, when her father asked her to give him the plastic necklace, Jenny would give him something else instead. One evening, after Jenny’s father read her a story, Jenny said, “Here, Dad.” She put her plastic pearl necklace into her father’s hand.

 Her father hold the necklace in one hand and opened the other hand. There was a real pearl necklace in it. He had had it for a long time, and waited for Jenny to give up the cheap one so that he could give her the real one.

     So, don’t be mean. If we are generous (慷慨的), maybe we will get something better.