【推荐1】In 1826, a Frenchman named Niepce needed pictures for his business. But he was not a good artist. So he invented a very simple camera (照相机). He put it in a window of his house and took a picture of his garden. That was the first photo.

The next important date in the history of photography (摄影术) was in 1837. That year, Daguerre, another Frenchman, took a picture of his reading room. He used a new kind of camera in a different way. In his picture you could see everything very clearly, even the smallest thing. This kind of photo was called a Daguerreotype.

Soon, other people began to use Daguerre’s way. Travelers brought back wonderful photos from all around the world. People took pictures of famous buildings, cities and mountains.

In about 1840, photography was developed. Then photographers could take pictures of people and moving things. That was not simple. The photographers had to carry a lot of films and other machines. But this did not stop them; for example, some in the United States worked so hard.

Mathew Brady was a famous American photographer. He took many pictures of great people. The pictures were unusual because they were very lifelike (栩栩如生的).

Photographers also became one kind of art by the end of the 19th century. Some photos were not just copies of the real world. They showed their feelings, like other kinds of art.

【推荐2】Now, it seems that artificial intelligence（人工智能）is becoming more and more popular in our life, and it has brought great effects on the ways we live, work and play.

Recently, a scientist has invented a special robot that can be a table tennis coach. That means people can learn how to play table tennis not only with humans but also with a robot.

Named Forpheus, the smart table tennis robot is quite special. It can study the movements of human players and the speeds of the ball. In this way, it can exactly judge the players' skill levels（水平）. Then it uses the information to change the ways to play. If the players are just beginners, Forpheus will play in a slow and easy way, but if the players are better ones, the robot will play in a faster and more difficult way. What's more, while playing, it encourages players to try their best with words like "Good job!", "Come on!" and so on. At the same time, it gives some good advice to improve their skills. So, it is both a good partner and clever coach.

Science and technology is developing quickly these days and no one knows what will happen in the future. "In the next 20 years, it will be possible that one robot teaches another to play table tennis or even invents another one!" Takurya, the inventor of the robot, said.

【推荐3】Scientists will put some robot fish into the sea near Spain this year. These robot fish will help people find out the pollution (污染)in the water. If the robot fish are able to finish their work successfully, the scientists hope the fish will be used in rivers, lakes and seas around the world.

The robot fish are about 1.5 metres long. There will be a detector (探测器) in each fish’s body. It can find the pollution in the water, and then the robot fish will eat part of it.

Unlike other robots, the robot fish don't need to be operated (操作) by people far away. The robots all have a big battery (电池) that can last for about eight hours. They can “swim” in the sea freely and send back information to people on the beach. After their batteries run down, they will go back to the beach by themselves.

There are five robot fish altogether. Each costs about 29,000 dollars. They are part of a three—year project by the joint effort of the engineering company BMT Group and University of Essex in England.

You must have many textbooks. After graduating old textbooks are thrown away, which is a big waste of money and paper.

According to a survey, students across the country buy 2.8 billion(十亿) new textbooks every year. If the following year’s students could reuse these textbooks, it would save over 20 billion yuan per year. That’s enough money to build 40,000 primary schools.

Primary and junior high school students in several Chinese cities are reusing music, arts, science and IT textbooks. That’s because students don’t have to take notes in their textbooks for these subjects, which makes them suitable for recycling. However, most of other textbooks still end up as waste. So we have to do something to stop it.

In fact, many countries already reuse their textbooks. In the US, book companies will come to schools and buy used books. They then resell them to new students the following year at a lower price. A high school textbook in the US can have up to eight owners before it is no longer in a good enough condition to be used. The books can then be recycled.

【推荐2】We use apps to order takeout, learn English and shop online. But have you ever imagined that we could deal with rubbish by using an app?

Dou Zheng, 15, a ninth-grader at The High School Affiliated to Beijing Norma University designed such an app. People can sell recyclable waste（可回收垃圾）like bottles to rubbish collectors. Just like ordering takeout, people can simply make an order on the app and enjoy door-to-door service. This March, Dou won the first prize at the 36th Beijing Youth Science Creation Competition with the app.

The idea for her app came from a real-life experience, On her way home, she always saw roads that were blocked（堵住）because of rubbish collectors. “There are lots of water bottles and cardboard on the roads. It’s a total mess,” she said.

After doing research on surrounding communities, she found that the answer to the problem was to change the way people and rubbish collectors trade.

Last summer holiday, she ordered a lot of takeout, which gave her the idea to design the app. To believe that it would work, she did surveys on WeChat and in the streets. The results showed that eight out of 10 people supported the idea.

However, she didn’t know how to program apps. She read many books and watched videos to learn about programming on her own. “It’s hard. I have to know what a series of complicated codes（复杂代码）mean and then write my own,” she said. Later, with the help of an app called AppMaker, she finished it! “This app made designing my app easier,” she said.

Her app may go online next year. “I’m working on contacting companies to promote（推广）it,” she said.

【推荐3】We all know that the environment is important to us all. We should always protect it from pollution. There is a discussion (讨论) on the Internet about the best ways to protect the environment.

We can do far more than these things in our daily life. Please protect the environment from small things. If you have any other good suggestions, please call us.