Sleep is something we all do. But some people need to sleep more than others. Babies sleep most of the time. Children in school sleep about ten to twelve hours a night. Most adults sleep only seven or eight hours.{#blank#}1{#/blank#}All parts of our bodies have to rest after they work.. Our arms need a rest after we lift heavy thing, When we run fast, our legs work hard. They get tired. We have to rest them. Our brains workhard, too.{#blank#}2{#/blank#} We can sit quite still and rest our arms andlegs. But our brains aren't resting. They go right on thinking as long as weare awake.

      Our brains slow down a bit when we sleep and dream.{#blank#}3{#/blank#} Instead of thinking wide-awake thoughts, our brains make up dreams. Some dreams are very pleasing. Some are not. Most of thetime we forget them when we wake up.

      Scientists have tried to find out what would happen if people were not allowed to sleep. They asked some people not to go to bed. The people stayed up all night and all the next day. They stayed up the next night too,and the day after. They played games, but they made mistakes. They forgot things.{#blank#}4{#/blank#} The people grew rude and mean. They became angry with their friends. Finally they were too tired to stand up. When they sat down, they fell asleep.

Scientists have found that if people are not allowed to sleep and to dream, they act in an unusual way.{#blank#}5{#/blank#}But we do know that we need it to stay well. So tonight have a goodsleep. Lie down under the covers. Shut your eyes. Let your thoughts wander.Soon you'll stop thinking. You'll be asleep.

A. It was hard for their tired brains to work.

B. When we are awake, they help us pay attention to the worldaround us

C. But babies, children, and adults—all of us need to haveour sleep

D. Good sleep helps to improve one's memory

E. No one knows why sleep is so good for us

F. But even as we sleep our brains are doing some work

G. Of course you will have a good sleep

Incredible experiences in Bucharest

    Admire one of the world's largest buildings

    The world's biggest parliamentary building, Palace of Parliament, happens to be in Bucharest. Hour-long guided tours manage to take in just a fraction of the building's three-million-plus square feet (there are more than a thousand rooms) and focus on the tons of marble, hardwood, and gold used in the building's construction in the 1980s, a time when Romania was trying to feed its own people. Ceausescu and his wife, Elena, both played a direct role in the construction. It was originally intended to house the presidential offices and the Central Committee of the Romanian Communist Party but was never finished.

    See remains of old “Paris”

    “Paris of the East” was Bucharest's nickname in the decades before World War II. Decades of communist misrule and a tragic earthquake in 1977 brought much of the old city down but there are places here and there where that former elegance can still be glimpsed. The Cismigiu Gardens in the center of the city is a pearl of park built around a romantic lake and featuring old-growth trees and gracious, wrought-iron signposts and benches.

    Learn about Romania's roots

    Walking though Bucharest's busy streets, it's easy to forget that outside the capital and a U large cities, Romania is a largely agricultural country, with a long and rich peasant tradition. The amazing Museum of the Romanian Peasant shows off the elaborate woodworking, pottery-making, egg-painting, and weaving skills of the peasantry in a way that's both educational and amusing. Small tongue-in-cheek signs at the entrance to each room poke fun at modern life, bring a chuckle, and draw you in. Downstairs there's a side exhibition on the Communists' efforts to nationalize the peasantry in the 1970s and 1980s.

    Appreciate 21st-century art

    Romania has exploded onto the contemporary art scene in recent years. The excitement was generated initially by a group of young painters and visual artists from the northern city of Cluj-Napoca, but at least some of the action has shifted to the capital as new galleries and design centers open up. It's hard to pinpoint precisely what constitutes Romanian contemporary art, though critics point to shared elements of wit and dark humor, a somber mood, and bits of surrealism in defining a common style.

    Google's new camera, called Clips, is a small, smart device. It comes with a case that has a clip (夹子)，but it's not designed to be worn on your clothing. Most interestingly, it uses artificial intelligence to take photography out of your hands so it can capture moments on its own.

    This roughly 2-inch by 2-inch camera, with a three-hour battery life and Gorilla Glass for toughness, is intended for candid moments, like when a child does something cute that may happen too quickly for you to pull out your smartphone.

On board the Clips device, it uses machine learning algorithms (计算程序) to help capture scenes. Those algorithms include face recognition. “Once it learns that there's a face you see frequently, it'll try to get nice photos of those faces,” said Juston Payne, the device's product manager. And they also want it to recognize facial expressions, which involved “training it to know what happiness looks like”. The Google team also trained it to recognize what not to shoot — like when a child's hand is over the lens, or if it is tossed in a dark purse.

    The only way to see the images is by connecting the camera with your phone, as it has no screen for viewing or editing.

    Were people concerned it could seem strange? Yes, Payne admitted. But they said they addressed that by making it obvious what it is. A green light on the front signals that it is on. Besides, unlike a camera meant to monitor your home, it is not connected to the Internet.

    “This product is only possible because of the way that silicon has advanced” Payne said, noting that it was only in the past year or so that they could squeeze the technology down into a device this size. Going forward, we're likely to get more assistance from the artificial intelligence packed into our apps and gadgets.

    Families should reduce exposure to synthetic chemicals found in food colorings, preservatives and packaging materials as a growing body of research shows they may harm children's health, according to a policy statement and technical report from the American Academy of Pediastrics released online.

    The statement also suggests improvements to the food additives regulatory system, including updating the scientific foundation of the U.S. Food and Drug Administrations safety assessment retesting all previously approved chemicals.

    Leonard Trasande, the author of the policy statement, to tell us more about these concerns.

Q: What are the growing number of studies showing us?

A: Over the past two decades, an accumulating body of science suggests some food additives can interfere with a child's hormones, growth and development.

    Potentially harmful effects of food additives are of special concern for children because they are more sensitive to chemical exposures because they eat and drink more relative to body weight, than adults do and are still growing and developing. An early injury to their organ systems can have lifelong and permanent consequences.

Q: What additives does the statement highlight?

A: The additives of most concern, based on rising research evidence cited in the report, include:

    Bisphenols, such as BPA, used to harden plastic containers and line metal cans, can act like estrogen（雌激素）in the body which may potentially change the timing of puberty, decrease fertility, increase body fat and affect the nervous and immune systems. BPA is now banned in baby bottles.

    Phthalates, which make plastic and vinyl tubes used in industrial food production flexible, may affect male genital development increase childhood obesity and contribute to cardiovascular disease. In 2017, the Consumer Product Safety Commission banned the use or some phthalates in child-care products such as teething rings.

    The Huaqing Palace Heritage Site

    Address: At the foot of Lishan Mountain in Lintong, 30 kilometers east of Xi'an.

    Opening hours: From March to November: 7:00-18:00;

    From December to February: 7:30-18:30.

    Bus routes: 914, 915, U5, and 306.

    On Sunday, November 3, 2019, most North Americans will mark the end of Daylight Saving Time (DST) by moving their clocks back an hour. This simple action will not only add an extra 60 minutes to their weekend, but also shift (变换，变动) daylight back into the morning hours, making it a little less painful to wake up for school and work during the shorter winter days.

    Operating the clocks was first suggested by Benjamin Franklin in 1784. He mentioned the idea in a letter to the editor of the Journal of Paris and advised it should be a way to save candles, but it was not taken seriously. George Hudson from New Zealand also recommended moving the clocks back two hours in 1895 to get extra daylight time to study insects. Unfortunately, neither he nor British people William Willett, who suggested it in 1907 as a way to save electricity costs, got their wish.

    It was the German Empire that began the clock shifting tradition on April 30, 1916, to save fuel needed to produce weapons and bombs for World War I. Though a few others, including the US and Britain, adopted the tradition shortly after, all the countries returned to Standard Time once the war ended, only to start DST again during World War II. Once the battle ended in 1945, the US government ended DST nationally but allowed states and districts to continue the tradition and even allowed them to establish their own start and stop dates.

    However, though there have been many attempts to persuade lawmakers to end DST, both in the US and Europe, they have not been successful. Therefore, unless you live in places like Hawaii and Arizona, you have little choice but to "Fall Back" and enjoy the extra hour this weekend! Health experts suggest the best way to adjust is going to bed at your regular time, even if the day is an hour longer.