Rush hour traffic is a problem in many big cities around the world. Commuters(上下班者)rush to and from their jobs in cars, buses, subways, trains, and even on bicycles. Large cities in the United States have two rush hours—one in the morning and one in the evening. But in cities in other parts of the world, there are four rush hours. In Athens and Rome, for example, many workers go home for lunch and a nap. After this midday break, they rush back to their jobs and work for a few more hours.

In Tokyo, there's a big rush hour underground. Most of the people in Tokyo take the subways. The trains are very crowded. Subway employees called packers wear white gloves and help pack the commuters into the trains when the doors close. They make sure that all purses, briefcases, clothes, and hands are inside the trains.

In Seoul, many commuters prefer to take taxis to get to work.. To hail a cab，many people stand at crossroads and raise two fingers. This means they'll pay the cab driver double the usual fare. Some people even raise three fingers! They'll pay three times the normal rate。

Streets in Rome are very crowded with automobiles and mopeds(摩托自行车)during rush hours. The city can't make its streets wider, and it can't build new highways, because it doesn't want to disturb the many historic sites in the city, such as the Forum and the Coliseum. It took the city fifteen years to construct a new subway system. Construction had to stop every time workers found old artifacts and discovered places of interest to archaeologists(考古学家).

In many big cities, there are special lanes on highways for carpools. These are groups of three or more people who drive to and from work together. They share the costs of gas and parking and take turns driving into the city.

Getting to work and getting home can be difficult in many places around the world. Rush hour traffic seems to be a universal problem.

1.Big cities have traffic problems during rush hours because there are _______

2.Most of the commuters in Tokyo _______

3.To “hail a cab” means to _______

4.Commuters in carpools probably_______