In Guang'an City, there are more and more cars on the roads. There are many traffic accidents. In order to work out the problem, the government decided to provide about 1,000 public bikes for people to rent（租赁）. The government encourages people to ride bikes in order to work out the traffic problem.

More than 13,000 people have agreed to the idea. Some of them ask for more than one card. Although there are not enough bikes, an official（官员）from the government says that they will find some ways to do with it.

People can get these bikes at special docking stations（停靠站）. There are about 100 docking stations in the city. Let's see the cost you need to pay. You should pay ￥100 for a bike card, and you needn't pay for it within 2 hours after you get the bike. About 2,000 cards have already been handed out to people, but only 800 cards can be used now.

The official from the government says they also need to face a lot of problems. For example, some bikes may be lost. But they say they will try their best to solve the problem.

A city without cars would be very strange, right? Venice is such a city.

Venice is in the northeast of Italy. It wasn't built on land, like Beijing or Shanghai, but on more than 110 islands. Seawater is everywhere around the city.

Even so, travel isn't difficult. The waterways have always been the best ways to get around. There are 117 waterways and more than 400 bridges that can guide you where you want to go.

People in Venice move from place to place by boat. They like to enjoy the scenery and cool summer nights while taking boat trips. They can talk to other people as they go along.

Venice grew out of small islands in saltwater lakes when some Italians escaped from a war more than 1,500 years ago, and built homes there.

Water makes the city special, but it is also a big problem.

Once, people used too much underground water. This made the city get lower little by little. Now the city has gone down by 23 centimeters. Another problem is the rising seawater. The temperature has risen over the years. This has made the ice of the Arctic Ocean(北冰洋)melt(融化).

Every year, high waters hit the city in autumn and winter. When a lot of water comes, more than half of the city is underwater.

Scientists are trying different ways to stop the city from getting even lower.