Ladies and gentlemen, I returned to this year in a time machine. In the year 2500, we are able to travel through time to any year in the history of the earth. This year is your last chance your lifestyle to save the earth.

    Beginning in the middle of the 20th century, a few people were worried about polluting the earth's water and air, but most people did not change their way of life. Instead, they continued to pour(倒) dangerous chemical(化学物品) and other waste into lakes and seas, to drive more and more cars and trucks, and to cut down trees.

By the year 2200, the earth's water was completely polluted. People could no longer drink water, and they had to use other types of liquids(液体). Scientists said that in the future there might be too many people on the earth. But not enough was done.

So by the year 2300, there were so many people that food became scarce. There was no water to grow food and all of the fish in lakes and seas died because of pollution. Terrible wars broke out between the rich and the poor. Scientists were working very hard to find another planet in space where humans could live.

By the year 2400, the air was too polluted for humans to breathe. So we had to leave the earth. But only the rich were able to leave. Where did we go? Nowhere. And everywhere. You see scientists did not find another safe planet, so now we must travel around the universe in our space ships. We are still looking for a place to call our home.

    So it is up to you to change history. There is still hope. You must change your lifestyle now, before it is too late.

    Have you heard about "Face Recognition (刷脸)" technology? It begins to become a popular and exciting development in China. In September 2017, a Kentucky Fried Chicken KPRO restaurant in Hangzhou utilized (利用) this new technology.

    Customers will go through the buffet (自助餐) line and then check out with their food using this "Just look with your face" payment method. When they get to the payment machine, they simply choose the Payment of facial recognition and then stand in front of the screen for 1-2 seconds. They then confirm their account and phone number and finish the payment process—all of it takes no more than 10 seconds!

    Nowadays, the words "Face Recognition" have become popular around China with the development of the ability to pay with facial recognition. Here are several examples of how you might hear the words in daily life in China. In Hangzhou, a high school provides a service where students can pay for meals by facial recognition. However, this isn't the only way we use the words in China! When you combine these characters together you also get another meaning: Jackie Chan got a dinner for free by "brushing his face".

    Do you know more about other meanings of "Face Recognition"? Please tell me more about it by sending an email to Susan2018@126.com or call me at 8524689. We'll talk about the topic next time.

    Different weather makes people feel different. It influences health, intelligence (智力) and feelings.

    In August, it is very hot and wet in the southern part of the United States. People there have heart trouble and other kinds of health problems during this month. In the Northeast and the Middle West, it is very hot at some times and very cold at other times. People in these states have more heart trouble after the weather changes in February or March.

    The weather can also influence intelligence. For example, in a scientific report, IQ (智商) of a group of students was very high when a very strong wind came, but after the strong wind, their IQ was 10% below. The wind can help people have more intelligence. Very hot weather, on the other hand (另一方面), can make it lower. Students in many schools of the United States often get worse on exams in the hot months of the year (July and August).

    Weather also has a strong influence on people's feelings. Winter may be a bad time for thin people. They usually feel cold during these months. They might feel unhappy during cold weather. But fat people may have a hard time in hot summer. At about 18 ℃, people become stronger.

    Low air pressure (气压) may make people forgetful People leave more bags on buses and in shops on low-pressure days. There is a "good weather" for health. People feel best at a temperature of about I8℃.

    Are you feeling sad, tired, forgetful, or unhappy today? It may be the weather's problem.

    Anyone who has had a long-term illness knows that recovering at home can be boring. This can be especially true for children. They may feel cut off from their friends and classmates. Now, these children may have a high-tech friend to help feel less lonely. That friend is a robot.

    The robot is called Avatarl (AV1). It takes their place at school. Through the robot, the children can hear their teachers and friends. They can also take part in classes from wherever they are recovering. And the children's school friends must help. They carry the robot between classes and place the robot in the classroom.

    A Norwegian(挪威的) company called “No Isolation” created the robot. There are another two co-founders, Karen Dolva and Marious Aabel. Dolva explains how the robot works. She says from home the child uses an iPad or a phone to start it, control the robot's movements with touch and talk through it. The child can take part in classroom activities. The robot is equipped with speakers, microphones and cameras that make communication easy. So it's the eyes, the ears and the voice of the child at school. Inside AV1 there is a small computer connected to a 4G network.

    AV1 is designed to be tough. It won't allow water to pass through it and can take a fall from a desk without damage. AV1 is large and looks like a human for a reason. Dolva says it can't be just a tiny camera because the other kids can't pick it up and take it with them. This is important because the robot is supposed to be a friend to the children. Hopefully AV1 will help some children feel less lonely while they were absent from class.

    Sitting too much is now listed with smoking and junk food as a bad habit that increases your risk of heart disease.

    New Australian research shows that half-an-hour in the gym will not make up for the waist-expanding damage caused by spending the rest of the day sitting.

    But the good news is that doing chores(家务杂事) in the house or gently walking around the office while on the phone might be enough to keep you fit.

    The study joins the growing body of evidence suggesting too much sitting might undo the benefits of exercise.

    The study measured the intensity(强度)of physical activities in 168 subjects over seven days. If found that, regardless of how much exercise they did or their total sitting time, those who took more breaks from sitting had lower risk of thick waists and lower levels of blood lipids(脂质).

    “Higher levels of blood lipids have been linked to a heightened risk of heart disease,”principal researcher Genevieve Healy of the University of Queensland said. "What the study shows is that there are benefits in just getting up regularly and interrupting your sitting time."

    Researchers behind the Stand up Australia project have written to the Rudd Government requesting $ 3.5 million for a two year study into how long sitting affects the health and productivity of workers.

    The latest study builds on work that is shifting the health promotion focus from purposeful exercise, such as running, to lower intensity activities throughout the day.

    The Australian research bas been backed up US studies, which show standing up is enough to double the metabolic(新陈代谢) rate and the amount of calories burnt.

    “To hold a body that weighs 77kilograms upright take a .fair amount of energy from muscles", said professor Marc Hamilton from the University of Missouri. "There is a large amount of energy associated with standing every day that cannot be easily replaced by, 30 to 60minutes in the gym."

    As space science develops, man has learned more and more about space. Space is not only amazing but also dangerous. While working in space, spacemen are facing danger as well as success.

    Scientists have found out that the radiation(辐射) is the greatest danger to spacemen in space. When spacemen are working in space, they are in danger of the radiation from the sun and other stars, which is bad for their health. The harm of the radiation won't be found until their children even grandchildren are born. Some special medicine may work a little, but no really effective medicine has been found so far.

    Space rubbish is also thought to be a great danger to spacemen. It's reported that there were 9,000 man-made things flying in space. About 30% of these are satellites, 10% are spaceships, and the rest are space rubbish. An explosion(爆炸) in space in 1999 made a cloud of 300,000 fragments, each at least 4 mm in size. A small piece of these even knocked a spaceship window and caused some damage(损坏). Scientists are watching and reporting any possible danger all the time. They are working to deal with space rubbish.

    Although space is really dangerous, it interests many people on the earth. In the near future, it may become possible for people to spend a few days in a space hotel. We may even choose to leave the earth and live in space in a few years. So we should do something to help improve the space environment.