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 for exploration. 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 Imagine at 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.

    27 world records were broken during the 2016 Summer Olympics. They fell in swimming running weightlifting and a number of other sports. But how do athletes continue to get better, jump longer, run or swim faster? Although scientists say that athletes have reached their limits (极限), records continue to fall. In almost every sport, athletes have become better since the Olympic Games begin.

    One reason is that and more people than ever before have access to sports and exercise. They start at an earlier age and can compete longer in their sport. In schools more and more natural talents can be discovered.

    Besides, athletes can train full-time instead of training after works. As medicine improves, athletes can stay in competition for a longer time and overcome injuries (损伤) faster. Many top athletes achieve their best results later on in their careers. Technology has also helped improve scores.

    One of the most important reasons, however, is the human mind. We always want to be better and faster that someone else. It can release (释放) great power in our body.

    So, where are limits? One of the most difficult questions to answer is how fast a human being can run. Many years ago, nobody thought a person could ever run within 10 seconds in the 100-metre race. But the record was broken at the 1968 Mexico City Olympics. A t the moment Sustain Bolt is the fastest man on Earth at 9.58 seconds. Scientists say that 9.48 may be the limit, but, who knows, maybe some runners will one day run within 9 seconds.

    Heritage (遗产) is traditional customs, history and beliefs. We use the word "heritage" in many different ways. People talk about their family heritage, city heritage and national heritage.

    Today, heritage is changing. The Internet connects people around the world. In many ways this is a good thing, because we can learn about the heritage of other countries, and we can show our own heritage to the world. However, some people worry that traditional heritage is disappearing. In many ways, countries are becoming more and more alike(相似的). In most countries around the world, you can find KFC. Nike shoes, Starbucks coffee. American movies and so on. Some people think this is a good change, and others don't like it. You can decide whether or not it's a good thing.

    However, everyone wants to protect traditional heritage, and sometimes this is hard. For example, when a new KFC opens in your city, a traditional restaurant might have to close.

    That is why heritage protection is so important. Heritage protection is a simple thought. It means keeping your country's or your city's heritage alive. People do this in many ways. The biggest part of heritage protection is probably preserving (保护) old buildings. Some suggestions of heritage protection are making sure your kids speak your traditional language, and teaching knowledge about heritage to them.

    The world is changing. No matter how it changes, never forget the heritage of our parents and grandparents.

    Cars make our lives more convenient. But they can also be a problem. For example, fossil fuel(化石燃料) cars mainly cause air pollution.

    To improve the environment, many countries are developing electric vehicles(EVs，电动车). Among them, China is' taking a leading role and has created the world's largest EV market.

    Last year, over 40 percent of the 753, 000 EVs sold in the world were sold in China, more than twice as large as the number sold in the United States.

    "Filling up a fossil fuel car with gas is more expensive than charging an electric car," said Wu Hao, who bought an electric car this year.

    However, there are still some problems. It can be hard to find charging piles and the cars can't go far before needing to be recharged.

    Some of these problems are being solved. In 2014, China had 31, 000 charging piles. Now China has the world's largest EV charging network, with more than 167，000 charging piles in total.

    Developing EVs is one of many efforts that China has made to cut down pressure on its environment after the government promised to stop increases in carbon dioxide emissions by 2030.

    "As China goes, so will the world's car industry," the Wall Street Journal said. China has taken a leading role in the world's electric vehicle industry.

Some students don't like math. They think it's difficult. What can you do to lean it?And here are some pieces of advice(建议). 

Listen well in class. The math teacher knows much, When you listen well, you can know much, too. So be a careful(认真的)student and listen well. And you can ask your math teacher for help if you don't know something in class. 

Ask your classmates for help. Your math teacher isn't always with you. When you find a problem(问题)too difficult, you can ask your classmates too. A classmate is a good friend. He or she must be happy to help you. 

Practise(练习)it every day. Do you want to be good at math?It needs time. You can't lean it well in a day. So practise it every day, and you can find it easy. Math is a great subject. La's learn it well. 

Dear Diary, 

The day didn't begin well. We had to present our project about an Australian animal today, but I{#blank#}1{#/blank#}(leave) the project poster on my desk. When I realized I didn't have it, I was halfway to school. I ran home {#blank#}2{#/blank#}(pick ) up the poster and then hurried to school.{#blank#}3{#/blank#}(luck), I got there in time for my {#blank#}4{#/blank#}(one) class, just be- fore the teacher arrived!

Our project presentation was about koalas. I gave the presentation together with David and Jenny. They are my best friends,{#blank#}5{#/blank#} it's easy to work with them. The presentation went well and our classmates really enjoyed it. Everyone loved the koala pictures on the poster! I was in{#blank#}6{#/blank#} great mood, and I didn't even mind that the next lesson was Maths, a subject I'm not good at. 

The weather was really nice, so I ate my lunch outside. My mum always{#blank#}7{#/blank#}(pack)a lunch box for me. Today I had an egg sandwich and a banana. 

The rest of the day flew by. In the afternoon, I had Art. Our class pointed {#blank#}8{#/blank#}(difference) Australian animals on a big wall. It's going to look really cool when it's finished. 

Jenny, David and I wanted to celebrate {#blank#}9{#/blank#}(we) success, so we went to the ice cream shop after school.{#blank#}10{#/blank#} a rocky start, it was the best day ever!