What is the sky?①This question is very difficult to answer.The sky is a space where there is nothing except the sun,the earth,the moon and all the stars.

Scientists can look at them through telescopes(望远镜) and,in this way,they can find out a great deal (许多,大量).They know many facts about the moon.For example,they know how big and how far away it is.②The moon is about 384,000 kilometers away from the earth.A plane cannot fly to the moon because there is no air.But a rocket can.

“How can a rocket fly?” If you want to know,get a balloon and then blow it up,until it is quite big.Do not tie up the neck of the balloon.Let it go!The balloon will fly off through the air very quickly.The air inside the balloon tries to get out through the neck of it,which pushes(推动)the balloon through the air.It does not need wings(翅膀)like a plane.③.Of course,the rocket is made of(由……制成) metal(金属).The metal must not be heavy but it must be very strong.There is a gas(气体) inside the rocket which is made very hot.When it rushes out of the rocket,the rocket is pushed up into the air.

Two schools in the UK are testing the use of body cameras worn by teachers to help keep the class in order. However, this way of controlling pupils has caused different discussions.

According to the school officials, pupils are not under surveillance (监视) at all times. Instead, the cameras are only turned on to record conflict (冲突) or bad behaviour among pupils in class. “Teachers say that they are spending their time managing order in the classroom instead of teaching,” said Tom Ellis, a person who supports the use of cameras. “So this technology might avoid some bad events and help teachers improve their teaching.” But students are told when they will be filmed by teachers, and any recorded footage (视频片段) is stored safely.

However, some people think it is a step too far. “If classroom incidents (事件) are so serious that teachers feel the need to wear cameras, then there are better ways to solve the problem. Surveillance is not the solution,” said one teacher who doesn’t support the cameras for classroom use.

So what’s your idea on this move? Do we really need body cameras in the classroom? Are those cameras the answer to classroom management?

In recent years, robots are becoming more and more popular. Robots have many different shapes. Some look like humans, and others look like animals. They can do lots of things, such as helping with the housework, building cars and so on. They will even do more things in the future.

A scientist thinks robots will be more intelligent than humans by 2029. His name is Ray Kurzweil. He works for Google in the USA. He is a leading expert on artificial intelligence (AI). Mr. Kurzweil says computers will learn from experiences, just like us. (A) 他还说他们将会讲笑话和故事。His 2029 prediction is a lot sooner than many people thought. In 1999, many experts said it would take hundreds of years for computers to be very intelligent. Now it won’t be long before computer intelligence is one billion times more powerful than the human brain.

Mr. Kurzweil joked that many years ago, people thought he was a little crazy. ( B) His thinking has stayed the same but everyone else has changed their thinking. He said his thoughts were not crazy any more. He said the rest of the world was changing its thought. He pointed to examples of high-tech things we use, see or read about every day. These make us think computers are intelligent. He said people changed because the public has seen things like voice-recognition technology, where you talk to a computer. He also said Google self-driving cars make people think about computer intelligence.

What will robots be like in the future? All of us don’t know. Computers and rockets didn’t seem possible more than 100 years ago. We believe that as long as we don’t give up, nothing is impossible.