2. A metro system is a grade-separated railway usually in an urban area with a high capacity and frequency of service.

Task 3 Thanks for using Metro (地铁) Clean, Modern, Safe and Easy to use. No wonder Metro is considered the nation's finest transit (公交) system. This guide tells how to use Metro, and the color-coded map on the inside will help you use Metro to get all around the Nation's Capital. Metro-rail fares • Each passenger needs a fare-card. (Up to two children under 5 may travel free with a paying customer.) • Fares are based on when and how far you ride. Pay regular fares on weekdays 5:30—9:30 a. m. and 3:00—7 :00 p. m. Pay reduced fares at all other times. • Large maps in each station show fares and travel times. Please ask the station manager if you have any questions. • Fare-card machines are in every station. Bring small banknotes because there are no change machines in the stations and fare-card machines only provide up to $ 5 in change (in coins). Some machines accept credit cards (信用卡). A Transit System Metro Features of the system: 1) ________ ________, 2) modern， 3) safe, and

The earliest ATO system on a full underground line was on the Barcelona Metro line 2 (now integrated on L5), which ran from 1963 until 1970 on its seven trains. Another one of the earliest examples of ATO was on the Victoria line of the London Underground, opened in 1968. The ATO system performs all functions of the driver except for the opening and closing of the doors. The driver only needs to press two buttons to start the train and, if the way is clear, then the train will automatically proceed to the next station.