If you will be cycling, you will need to know what these traffic signs and signals mean.

    A sign like this one means that there is a bike lane（道）. If there is a bike lane, you are required to use it. If there is not a bike lane, you should ride with traffic as far to the right side of the road as possible.

    When the signal light turns green, cars go. When you cross the street at a signal light, you should wait for the walk signal. Be sure to look carefully to the left, right and left again, before crossing the street.

    When the signal light turns yellow, car drivers should slow down and prepare to stop. You should not cross if the light is yellow. The light is about to turn red, and cars will enter the intersection(十字路口).

    This signal is the WALK sign. It has a picture of a person walking instead of using the word WALK.

    This signal is the DON'T WALK sign. It is part of the signal with the picture of a person walking. This is a picture of a red hand, meaning you should stop. You should wait to cross the street until the green picture of the person walking is showing.

    Car drivers and bikers must come to a complete stop at STOP signs.

    A yield sign means to slow down and be ready to stop. If there are pedestrians（行人）or vehicles in or nearing the intersection, you must stop. If there is no traffic in or nearing the intersection and it is safe, you may go through.

    This sign means you are coming to a crosswalk. Car drivers and bikers must stop to allow people in the crosswalk to cross the street.

    The Great Pyramid(金字塔)was built nearly 5,000 years ago for a king called Khufu. It is on the west bank of the Nile River. In fact, all the pyramids along the Nile River are on its west bank. The ancient Egyptians thought of the rising of the sun as the beginning of life and the setting of the sun as the end of life. This is why their bodies were buried on the west of the Nile.

    It is very hard to realize just how big the Great pyramid is. It has over 2,000,000 pieces of stones. Most of these big stones weigh two and a half tons each. Some even weigh fifteen tons. Without machinery, the ancient Egyptians cut and moved and lifted each of these stones. Almost all the stones came from the east bank of the Nile, and they were taken across the river in boat. It took more than 100,000 people twenty years to build the Great Pyramid.

    The Great Pyramid is over 450 feet high today. Each of the sides of the Pyramid is 755 feet long. It takes about twenty minutes to walk all the way around it.

    One of the newest words on the coffee stage is “shade grown coffee”. Shade grown coffee isn't new. In fact, until only a few years ago, shade grown coffee represented the major coffee beans sold on the world coffee market. The coffee plant is a natural shade lover, growing best in the shade afforded by an overgrowing canopy (树冠) of rain forest plants. That canopy protects the coffee plant from sunlight that reduces its production and kills it.

    Shade grown coffee is, however, more expensive to grow, at least in the short run. Growing coffee in the shade means that coffee growers also have to spend time working on the protectors. It means that less land is left to produce coffee beans. The arrival of technically engineered coffee plants that grow well in the sun represented a major development in coffee industry. Because there was no need to grow shade trees to protect the coffee trees, farmers could use more and more land to grow coffee trees, increasing their productivity and leading to more money for the coffee plantations (种植园) and farmers.

    However, it was not a good idea to move away from shade grown coffee. The sheltering canopy provided more than just shade for the coffee trees. Those plants provided shelter for birds and other animals who feed on pests.

    They help to fix nitrogen in the soil, and nitrogen is a natural fertilizer which makes plants grow more successfully. The increase in land used to grow sun loving coffee trees also had an unexpected effect on the law of supply and demand. The increased production resulted in a huge amount of coffee beans coming to the market, which brought down prices.

Moreover, most experts agree that shade grown coffee is better in taste than coffee grown in full sun. Plants grown in shade take longer to develop. The slower growing time helps to improve the coffee's taste. You can buy a can of shade grown coffee to replace your usual sun coffee. One cup of coffee a day—it's a small price to pay for a better world.

    Your next car could have two seats, three wheels — two in front and one in the back and a top speed of more than 100 miles per hour. Elio Motors plans to make such a tiny car named the Elio. Its two seats sit front and back instead of side by side. The driver is positioned in the center with the passenger directly behind.

    The starting price for the car is just $6,800. It has only one door, on the left side, which cuts a few hundred dollars off the manufacturing costs. Having three wheels also makes it cheaper. It has air conditioning, power windows and door locks and an AM/FM radio. More features can be ordered through Elio's long list of suppliers. Elio will also sell the cars directly through its own stores and not through franchised dealers (特约经销商).

    Paul Elio dreamed as a kid that he would one day own a car company called Elio Motors. In 2008, tired of high gas prices, he started working on a car that burns gas in a more effective way. Equally important to him was creating U.S. manufacturing jobs and making the car inexpensive enough to attract buyers who might otherwise be stuck in their old, unreliable cars. “Whatever matters to you, this can move the needle on it,” he said.

    Already, more than 27,000 people have reserved (预订) one. Paul hopes to make 250,000 cars a year by 2016. So far, reservation holders are those who will use the Elio as a second or third car for work. Finally, though, he believes the car will interest high school and college students as well as used-car drivers who want something newer and more reliable.

    Like all big cities, Paris has a traffic problem: lots of cars, lots of traffic jams (阻塞) and lots of pollution from exhaust fumes (废气). So the city began a scheme (计划) to improve the situation.

    Under the Velib scheme ('Velib' comes from vélo liberté, or 'bicycle freedom') people can take a bicycle, use it for as long as they want, and then leave it at the same or another bicycle station. The first half-hour on the bike is free, but if you don't return it after 30 minutes, you have to pay. But it's only €1 a day or €29 a year! The bicycles are heavy (25 kg), and they are all grey and have baskets. There are about 20,000 of them in the city, and around 1,450 bicycle stations. So there are a lot more Velib stations than the 298 subway stations!

    Paris is not the first city to have a scheme like this. But not everybody thinks it's a great idea. One Parisian said, 'These bicycles are only for short journeys. If people want to travel across the city, they won't use a bicycle—they'll still use their cars.'

    A city spokesman said, "The bicycle scheme won't solve all our traffic problems, of course. But it might help reduce air pollution. Traffic, together with factory fumes, is a big problem. There aren't any simple answers to traffic problems and pollution in cities. But unless we do something now, there will be more traffic jams and temperatures will continue to rise, so the problems in our environment will get worse. The bikes might help people to lead a healthier life, too."

Lack of sleep among children and teenagers in China has worsened in the past decade, with more than 80 percent getting insufficient sleep on school days, a new report has found.

Chinese youngsters snooze 7. 8 hours a night on average on school days, down 0. 3 hours from 2009, according to the report released on Monday by the Chinese Academy of Sciences'Institute of Psychology.

Researchers surveyed more than 15,800 students from Henan, Hebei and Guangdong provinces from April to July, asking what time they go to bed and wake up on days they take offline classes on campus.

Only 46. 4 percent of them sleep for at least 8 hours, compared with 47. 4 percent in 2009.

According to an action plan laying out measures to be taken from 2019 to 2030 to promote the health of citizens, primary school students are recommended to get a minimum of 10 hours of sleep a night. For junior high school and senior high school students, the recommended sleep durations per night are 9 and 8 hours respectively.

By this set of standards, more than 95 percent of students from primary schools, nearly 91 percent at junior high and 84 percent at senior high, did not get enough sleep on school days, heightening the risk of them developing cognitive, mental and physical health problems, the report said.

Hou Jinqin, a researcher at the National Institute of Education Sciences who co-authored the study, suggested local authorities implement measures instructed by the Ministry of Education, such as lessening academic burdens, postponing start times at school and encouraging children to be enrolled at institutions closer to home, in order to prolong sleeping hours.

In terms of the COVID - 19 outbreak's impact on sleep, she said available research overseas shows school closures forced by the COVID - 19 epidemic have added two hours of sleep to young students studying-gat home.

In China, some studies have revealed no marked differences in sleeping patterns of students before and after school reopened, she added.