Have you seen some machines that eat used plastic bottles and give some coins to the users(用户) ?

     Recently, such machines have appeared at universities in Chongqing. They can turn rubbish into treasure and encourage the public to recycle rubbish. The machine is as large as a fridge. Users put an empty bottle in the machine, It is identified(识别) by a  small camera. Then it is put into a built-in bin. The users can get some coins. They can also give away the money.

     When the machine is filled with bottles. it will tell the company's(公司) head office. Nearby stations will send workers to have bottles collected . packed and send to the company.

     The bottle recycling machines could greatly encourage the public to recycle rubbish and save natural resources(资源) . Now the machine only eats plastic bottles. At sometimes in the future it will also cover others, such as glass bottles, to turn more rubbish into treasure and make full use of the natural resources.

     People can also see similar machines in Shanghai. In the future, more such machines will appear at some large stations. Bus stops, neighborhoods and schools.

    In the Charles F. Johnson Elementary School in New York, there is a special radio. It gives people warnings about bad weather.

    One day, there came a sound from the radio. This sound brought the piece of news: a heavy storm was coming. William Tomic, principal(校长) of the school, asked teachers to bring children indoors and put them in a safe place at once.

    Minutes later, the storm came. However, because of the warning of the radio and the quick work of the principal, no one was hurt.

    "The radio really did work very well.(A)(我们对它的工作感到很满意), "William Tomic said. "The parents were happy as well."

    The U. S. government hopes there will be more such successful stories. It plans to give this kind of radio to all 97, 000 public schools in the country.

    Every year, more than 10, 000 big thunderstorms, 2, 500 floods, 1, 000 tornadoes(龙卷风) and some hurricanes(飓风) take place in the U. S., so the warning radios are very useful. They not only give people warnings about bad weather, but also give warnings about other dangerous  things.

D

    The earth moves round the sun , and the moon moves round the earth . When our part of the earth faces the moon , it is night .

    The sun is much bigger than the moon . But sometimes the moon looks bigger than the sun , because it's much nearer to the earth

    The sun is very bright . It gives off very strong light . The moon looks quite bright , too. But it doesn't give off any light at all .

    The moon looks much bigger and brighter than the stars . But actually the stars are much bigger and brighter than the moon . They look smaller than the moon because they're much farther away from us .

    Three powerful ocean storms hit the Caribbean, the coast of the southeastern United States and southeastern Mexico. They come as the state of Texas recovers from Hurricane Harvey (飓风哈维). The huge storm caused serious flooding and billions of dollars in damage in Houston, the country's fourth-largest city.

    Hurricane season in the Atlantic Ocean goes from June 1 to November 30. And most storm activities happen in me month of September.

    Hurricanes are the most powerful storms in the Earth's atmosphere. The storms have different names depending on where they take place. Scientists call all these storm tropical cyclones (热带气旋).

    If the storms form over the Atlantic Ocean or eastern Pacific Ocean, they are called hurricanes. Storms that form in the western Pacific Ocean are known as typhoons. In the Indian Ocean, they are called cyclones. Although they have different names, all these storms form in the same way.

    Scientists at the American space agency NASA describe tropical cyclones as huge weather "engines" that use warm, moist (潮湿的) air as fuel.

    They can only form over warm, tropical waters near the equator (赤道).

    A tropical cyclone develops when warm moist air near the surface of me ocean rises. This creates an area of unusually low air pressure.

    Higher-pressure air from surrounding areas pushes in to take the place of the warm, rising air. It becomes warmer and moister and rises, too.

    The rising, moist air goes high into the atmosphere, where temperatures are low. This creates wind. The moisture forms clouds. The developing weather system begins to spin because of the Earth's rotation (旋转).

    As the storm spins faster and faster, an "eye" of the storm develops at its centre. This is a calm area of very low pressure. Higher pressure air from above flows down into the eye.

    Let's take a look at the cool inventions in science and technology.

Robot-teacher

    Some students in South Korea have new language instructors: the English-teaching robots. The robots help students practise speaking English. South Korea employs many foreigners to teach English. The robot-teachers can help to solve a shortage of English teachers. Can robots replace human teachers one day?

Superhero suit

    Have you ever dreamed of becoming a superhero? There's a real Iron Man suit, XOS 2. The suit provides the power to lift 200 pounds and break the wood easily. It was designed to help the military with heavy lifting. One person in the suit can do the work of three soldiers.

Hard-working robot

    The EMIEW2 robot is a perfect office helper. It can guide visitors to the places they want to go. The three-foot-tall robot can know different human voices and react to instructions. One day, it may work as a receptionist or a guard.

    People have understood that kindness is good for the person who receives help. For example, when we give food to a hungry person, he is lucky. However, scientists have recently begun to study the effect(影响)of the kindness on the person giving it. What they have found is that doing good is good for the doer(行为者).Acts of kindness can improve health, help a person reach goals and even add years to a person's life.

    The first study to show the connection between doing good and living a long life was a study on aging(衰老). Beginning in 1956, scientists studied a group of married mothers for 30 years. They thought the women with the most children would die first. But the number of children a woman had did not matter. Wealth did not matter. Education did not matter. What did matter was whether they volunteered. Women that volunteered had fewer diseases during their life.

    Many other studies have found the same positive(积极的)effects. Helping other people improves long-term health. The gains are the same for men, women, old people and the young. Those who volunteered had fewer serious diseases than those who did not volunteer. This included diseases such as heart attack, cancer and stroke.

    Scientists are studying many possible causes. One possible cause is an increase in antibodies(抗体)，which help fight against disease. One study showed the body produces more antibodies after an act of kindness.

    Another one is an increase in Oxytocin(催生素)，it is a chemical that fights the effects of stress from life. Scientists have found a link between being kind to people and an increase in the chemical oxytocin.