Bikesharing is a new choice for short journeys in cities. It is good to the 1 development of the big cities.
A 2 by a company found that shared bikes started the nation's 3 for bikes again. Now more and more Chinese people are 4 bikes instead of cars to make short journeys in cities.
An engineer of that company says that since the 5 of shared bikes, people have made fewer trips by car. The love for shared bikes is not only among 6 people, who were born in the 1980s and 1990s, but also among people over sixty.
At weekends, the number of the riders in Shenzhen reaches the 7 of all cities. On weekdays, the number of people who use shared bikes to travel to work is 8 in Shanghai.
It is said that bikesharing will help 9 the cities' environment. It not only helps solve the traffic problems, but also will help to make more use of 10 in cities. Take Beijing as an example. If more people choose shared bikes, an area of five Bird's Nest stadiums (体育场)will be saved.
When the weather is hot, you go to a lake or an ocean. When you are near a lake or an ocean，you feel cool. Why？The sun makes the earth hot but it cannot make the water very hot. Although the air over the earth becomes hot，the air over the water stays cool. The hot air over the earth goes up. Then the cool air over the water moves in and takes the place of the hot air. When it moves in，you will feel the wind. And the wind makes you cool.
Of course，scientists cannot answer all of our questions. If we ask "Why is the ocean full of salt？"，scientists will say that the salt comes from rocks. When a rock gets very hot or very cold，it cracks(断裂). Rain falls into the cracks and then carries the salt into the ocean. But then we ask，"What happens to the salt in the ocean？"The ocean does not get saltier every year. Scientists are not sure about the answer to this question.
We know a lot about our world. But there are still many answers which we don't have and are curious(好奇的) about.
