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    What is a Chinatown? Is it a town in China? Of course not! It is in a foreign(外国的) country. It is a place where many overseas(海外的) Chinese live together.

    There are lots of Chinatowns in America. The biggest one is in New York. There are about 150,000 people in it. It is the home of Chinese New Yorkers. And it is also a good place to go.

    Shopping in Chinatown

    Shopping in Chinatown is fun. You can find lots of things there. Most of them are made in China. Mott Street is the best place to shop because the things there are very cheap.

    Eating in Chinatown

    Chinatown has more than 200 restaurants. You can enjoy traditional (传统的) Chinese food there. New Silver Palace Restaurant is one of the best restaurants. Why don't you have breakfast with a cup of green tea in it? You can eat some Shanghai food in Evergreen Restaurant.

    Living in Chinatown

    Living in Chinatown is comfortable. You can find hospitals, schools, banks, libraries and supermarkets in it. In some schools, students must study Chinese. Many overseas Chinese send their children to these schools. They want their children to learn more about China and its culture(文化).

    Almost all animals need to sleep to stay healthy. But sleeping can also be dangerous because other animals may hurt those who are sleeping. This leads to many different ways of sleeping that help them stay safe. Some of these ways may surprise you!

    Almost all bats sleep upside down. They hang from a branch of a tree or the ceiling of a cave. Up high, bats are safe from most other animals. If they are in danger, they just fly away.

    A dolphin sleeps with just half its brain at a time. It must stay awake to breathe and to watch for danger. Dolphin mothers and babies can go without sleep for as long as two months to stay safe.

    Some ducks sleep with just half their brains, too. These ducks often sleep in a line. The ducks at both ends help to keep the group safe. They keep one eye open to watch for danger. The ducks in the middle sleep deeply with both eyes closed.

    Seals breathe air, but that doesn't stop some of them from sleeping underwater. They hold their breath and dive deep to sleep for up to twenty minutes at a time. Sleeping deep underwater helps these seals stay safe from animals that hunt them near the surface.

    Horses often sleep standing up. Their legs lock in place so they don't fall over. If a horse is lying down, it needs a long time to get up. A horse can run from danger more quickly if it is already standing.

    A flamingo can sleep while standing on one leg. The standing leg locks so it stays straight. The other leg remains close to the flamingo's body. Its head rests on its back. A flamingo lives (and sleeps) near many other birds to stay safe.

    Some seabirds can sleep while they fly. These large birds spend most of their lives over the ocean. They are in danger on the water, but they are safe in the air. They fly for many hours without flapping（拍打）their wings. Sometimes they sleep while they are flying.

    Would you like to sleep how they sleep?

    How long is a year? Most people say a year is 365 days. It takes about 365 days for the earth to go around the sun. In fact, it takes a little longer for the earth to go around the sun. It needs 365 days, 5 hours, 48 minutes, and 46 seconds.

    If a year has only 365 days, what happens to the extra(额外的) 5 hours, 48 minutes, and 46 seconds? The answer is this: Every four years, we have another day. It's February 29, and we call this day " a leap day(闰日)".This kind of year is called "a leap year". A leap year has 366 days.

People born on February 29 are called leap-day babies, or leapers. There are about four million leapers in the world. When do they celebrate their birthday? Do they celebrate only once every four years? Some leapers celebrate the birthday on February 28, and others celebrate it on March 1. Think about it: A twelve-year-old leaper may have celebrated only three birthdays on the real day after he or she was born!

    Which year are leap years? Years that can be divided(除尽)by four are leap years. The year 2000 was a leap year. Then 2004,2008,2012,2016 were the next leap years. If you know a leaper, you must say "Happy birthday!" to him or her on the leap day, because you just have one time to do that every four years!

    The years from A.D 500 to 1450 are called the Middle ages. Sometimes they are also called the Dark Ages since few people had an education during that time. Still, there were lots of new ideas and inventions. Many of them came from China.

    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 many as the number sold in the United States.

    "Filling up a fossil fuel car with gas(汽油) is more expensive than charging( 充电) 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(充电桩) 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(二氧化碳排放量) 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.