The world’s first subway was built in London in 1863. At the time, the government was looking for a way to reduce traffic problems in the city of London. The poor areas of the city were so crowded with people that it was almost impossible for horse carriages (the taxis of those days ) to get around. The city officials were interested in trying to make it possible for workers to live outside of London and travel easily to work each day. If people had a cheap and convenient way that they could depend on to get to and from work, they would relocate their homes outside of the city. This would help ease the pressure of too many people living in the poor parts of London. From these problems, the idea of the London Underground, the first subway system, was born. The plans for building the Underground met with several problems and delays, but the first track was finally opened in January 1863. A steam train pulled the cars along the first underground track which was six kilometers (3.7 miles ) long. About 30,000 people got on the subway the first day. Riders were treated to comfortable seats (standing up while the train was moving was not allowed ) and pleasant decorations inside each of the cars. However, the smoke from the engine soon filled the air in the tunnels with ash and soot, as well as chemical gases. Fans had to be put in the tunnels later to keep the air clean enough for people to breathe. Even with its problems, riding the underground did become popular. It carried nine million riders in its first year. Modern subways have come a long way since the early days of the London Underground. Today there are 94 large underground rapid transit systems around the world. The busiest of these subway systems is the Tokyo Metro which opened in 1927. This efficient subway has two billion riders per year, and “pushers ” work on the platforms during busy traffic hours to help push riders onto trains. At times, subway cars have been packed with up to 300 people! Shopping malls built in high traffic stations where riders move from one train to another have also helped the popularity of subways in Tokyo. Stations like the famous Ginza Sugo Eki Ginza Consolidated Station include underground department store, supermarkets, restaurants, and specialty shops. Shoppers never have to go above ground! What does “Shoppers never have to go above ground!”mean (Please answer within 10 words) ________________________________________________________