Imagine this. You come back from school and your robot housekeeper is already waiting for you at the door. He turns on the lights, air-conditioner and television. While you are having dinner, he cleans the floor. Before you go to sleep, he tells you the weather report, then reads you a bedtime story.

Such thoughts are not just for stories. Now they can happen in the real world, as long as you have the robot Alpha 2. Alpha 2 was a star at the 2017 World Robot Conference(大会), which was held from August 23^rd to 27^th in Beijing. More than 150 universities and companies from across the world brought their robots to the event for show and sale. Some robots work in factories. Some robots go to outer space or under water forexploration. But the highlights(亮点)of the event were service robots.

This kind of robot is the closest to our daily lives. From cleaning to teaching, music to sports, service robots have been used to do many kinds of jobs.

Teo is a popular service robot, as well as an artist and music teacher. His 53 fingers help him play the piano well. He played John Lennon’s song Imagineat the conference.

There is another service robot called Bestic. It acts as a human arm to feed people with a spoon. It can be a good helper for little kids, the elderly and those with difficulties using their hands.

The scientists believe that it may not be far when every family has at least one service robot.

Have you ever dreamed about a trip to space? Seeds(种子) of some vegetables are much luckier than you, because they travelled to space and went back to the earth again.

   Since 1987, China has sent about 1,000 kinds of seeds into space. These include peppers(辣椒), tomatoes, cucumbers and carrots. Even on China’s Shenzhou Ⅴ, there were some seeds from Taiwan.

   Many things in outer space can bring big changes in the seeds like the radiation(辐射) and low gravity(重力). But not all seeds are better after going to space. After returning to the earth, the best seeds are picked. The vegetables growing from these best seeds grow faster and bigger than common(普通的) seeds. We call them “space vegetables”. Some people worry about eating space vegetables. They think that space vegetables might not be good for us and could make us get sick because of the changes of their genes(基因). In fact, no new genes are put into the space vegetables, so they are surely healthy.

   Space vegetables are better than common vegetables. For example, space tomatoes stay fresh for twenty days. It is one week longer than common tomatoes. Another popular space vegetable is the pepper. Space peppers have 20% more vitamin C than common peppers. People can buy these space vegetables in the market with prices 30—50 % higher than their common ones.

The world itself is becoming much smaller by using modern traffic and TV, telephone and so on. Life today is much easier than it was hundreds of years ago, but it has also brought new problems. One of the biggest is pollution.

Pollution comes in many ways. We see it, smell it, drink it and even hear it.

The more people, the more pollution. Many years ago, the problem was not so serious because there were not so many people. Man is now slowly polluting the whole world. Air pollution is still the most serious. It’s bad to all living things in the world. Water pollution kills our fish and pollutes our drinking water. Noise pollution makes us become angry more easily.

Many countries are making rules to fight pollution. They stop people from burning coal in houses and factories in the city.

The pollution of SO--₂ is now the most dangerous problem of air pollution. It is caused by heavy traffic. It is sure that if there are fewer people driving, there will be less air pollution.

Early in the morning, at noon, or in the evening in the big city and in the countryside, all across the United States, you can see Americans running. Men and women,  (1)  and old are running. People run   (2)  along the beaches of California,  (3)  Central Park in New York, down quiet streets in small towns or at the gyms.

    Running didnˈt use to be so popular. In the 1960s, runners were  (4)  athletes and healthy strong people. In those days, when people saw a runner, they used to ask, "Hey, whatˈs the hurry for?" or they might say to  (5)  , "Is he crazy?" Women almost never  (6)  . If they did, they might hear a man shout, "If I catch you, can I keep you?" But today all these have  (7)  . Men and women of all  (8)  enjoy running.

    Doctors say many of the health problems in the United States come from these bad habits: eating too much, smoking cigarettes, and exercising too  (9)  . Doctors tell us, "Eat less, donˈt smoke, and exercise more." Running helps most people  (10)  weight. And it is also good exercise because it helps build strong hearts and lungs.

Fast walking is the exercise between walking and race walking. A study shows that fast walking has become the most popular exercise in China and many people walk more than 5,000 steps a day. The results of the study are from QQ users. About 37% of the people choose fast walking as their favorite exercise; over 23% choose running and more than 14% choose riding bikes.

Fast walking and running are easy, cost little and work well, so they are popular. And many people would rather do exercise in nature than go to gyms (健身房). Itˈs best to walk fast for at least 10 minutes at one time and walk up to 6,000 steps every day.

The study also shows that people in Guiyang, Guizhou love sports most. On average (平均), everyone there walks 5,941 steps every day. It seems that people in places with better environment and air are more willing to (更愿意) do sports.

   Some people live in high mountains. The air up high is thin. Mountains people are used to the thin air. They feel good when they live up high.

    Most people live in low places. If they go up high, their head hurts and they sometimes feel dizzy (头晕目眩的) and sick. They have to breathe faster. Their hearts beat faster. They have to move slowly. If they stay up high for a long time, their bodies will change. Their lungs will become large. Their larger lungs will help them to breathe the thin air.

    Airplanes fly high over the mountains. Big planes have enough air so the people inside won't get dizzy. The air gets thinner as you go higher. Out in space there is no air at all.

    In California, South America, most people live far up on the mountains. Sometimes they go down to the low country. People living there feel fine. But the people from the mountains feel sick.

Can plants eat people? Probably not, but there are many plants that eat meat. Some of them are big, and they can eat small animals. One famous meat-eating plant is the Venus flytrap (捕蝇草).

The Venus flytrap is a very strange plant. It grows in dry parts of the United States. Its leaves are like the pages of a book. They can open and close very quickly. Inside the leaves, there are three small hairs. If a fly touches one of the hairs, the leaves closes quickly. The fly cannot get out. In about half an hour, the leaves press the fly until it is dead. Then, the plant covers the fly. Slowly, the plant eats the fly.

Why do plants do it? Most plants get what they need from the sun, the air, and the ground. In some places, the ground is very poor. It doesn’t have all these important things, especially nitrogen (氮). So some plants eat meat to get what they need. Let’s hope that some of the bigger plants don’t get the same idea!

Most of us know that the weather can affect our feelings. But do you know why? And how does the weather affect our moods? Scientists give us answers from their research(研究).

People often say the shining sun makes them happy while cloudy day makes them sad. It’s true that sunlight makes us feel good. When the sun shines on us, our bodies will produce(产生) vitamin D. Vitamin D is necessary and important for people to keep healthy. It can make us feel active and happy. For example, many people in Iceland(冰岛), Norway(挪威) and Finland(芬兰) often feel sad because there is little sunlight. The winters there are long and dark. Less sunlight makes their bodies produce less vitamin D. So scientists built special “sunrooms” with man-made lights to help people feel better in these countries. People can go there and enjoy the “sunlight” for a few hours every week.

      We live in a much better life than we used to. However, health is still a problem all over the world. Sometimes it seems quite serious.

      People need more health care, especially in developing countries. Look at the following table made by World Health Organization (WHO).

      The table shows that developed countries have 20 per cent of the world's population but take 90 per cent of the health care. For example, a Japanese spends five hundred dollars on health care every year. However, a person in a poor country spends only three dollars a year!

      There is another health problem in developing countries. Fifty years ago, people lived a life of about forty-six years on average(平均).Now most people in the world live twenty years longer than before. People in the poorest countries, however, live a much shorter life than people in developed countries. There are thousands of patients in poor countries; most of them are children. In 2002, almost 57,000,000 people died of different kinds of diseases. And nearly 20 per cent were children under five.

    It's time for us to do something to help these children!

I think it is safe to say that snakes are not popular among most people. It would be hard to find a person who is neutral(中立的), or simply doesn't care one way or the other. What I wonder is why something even without legs causes such great fear.

   Snakes are quite useful, but that doesn't seem to matter. Snakes help control the population of mice. Without snakes, perhaps we would find mice everywhere. Most of us, however, would rather see a mouse than a snake.

   The poison argument is a strong one. Some snakes are poisonous, and this causes people's death. However, the poisonous snakes are only a small number. We can't say all the snakes are bad just because of a few dangerous ones.

   And what do we do with the people who really like snakes? They like snakes even more strongly than we dislike them. These people learn about them, find them out, and watch them carefully. Why? The only reason I can think of is that these people are open-minded. They are able to put aside differences and welcome the snake as a friend.

   Whatever the reason for our like or dislike, snakes do something good in the circle of life. They would prefer to be left alone, and that is what we should do. If you're lucky, you might not run across more than a few of them in a lifetime. That would be fine with most of us.