1．
In 1863 the first underground passenger railway in the world opened in London．It ran for just under seven kilometers and allowed people to avoid terrible （1） ______ （crowd） on the roads above as they travelled to and （2） ______ work．It took three years to complete and was built using an interesting method．This included digging up the road，（3） ______ （lay） the track and then building a strong roof over （4） ______ top．When all those had been done，the road surface was replaced．
Steam engines（5） ______ （use） to pull the carriages and it must have been（6） ______ （fair）unpleasant for the passsengers，with all the smoke and noise．However，the railway quickly proved to be a great success and within six months，more than 25，000 people were using （7） ______ every day．
Later，engineers（8） ______ （manage） to construct railways in a system of deep tunnels （隧道），which became known as the tube．This development was only possible with the （9） ______ （introduce）of electric-powered engines and lifts．The Central London Railway was one of the most（10） ______ （success） of these new lines，and was opened in 1900．It had white-painted tunnels and bright red carriages，and proved extremely popular with the public．