用方框中所给的单词的适当形式填空，使短文正确、通顺。每词限用一次。

seat  hold  start  arrive  old  hurry  travel  crowd  provide  comfort

Many large cities have a subway system. The subway is called tube in London. In San Francisco, it is called BART (Bay Area Rapid Transit). Some subway systems, like Chicago’s, are quite ____________. It opened in 1897. Others are more recent (近代的). For example, Mexico City’s subway ____________ in 1969.
Most subways are very modern and clean, but sometimes they get very____________. So people have to follow certain rules to make the trip more ____________. In London, when people use the tube, they must stand on the right so that people in a ____________ can walk on the left. They let passengers get off the train before others get on, and people are expected to give their ____________ to the old and disabled people.
Some subways ____________ excellent services. In most subways, there is a station about every one kilometer. Trains ____________ at a station about every two minutes. Subways carry a lot of passengers. The number of people ____________ one way each hour in London can be about 30,000. However, in some other cities it is much higher. Hong Kong’s subway____________ the record of about 80,000 passengers an hour!