【2017 真题体验】 第二节（共 10 小题；每小题 1.5 分，满分 15 分） 阅读下面短文，在空白处填入 1 个适当的单词或括号内单词的正确形式。
In 1863the first underground passenger railway in the world opened in London. It ran for just under seven kilometers and allowed people to avoid terrible __61__(crowd) on the roads above as they travelled to and ___62__ work. It took three years to complete and was built using an interesting method. This included digging up the road, ____63___(lay) the track and then building a strong roof over___64___ top. When all those had been done, the road surface was replaced. Steam engines ___65__(use) to pull the carriages and it must have been___66__(fair)unpleasant for the passengers, 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___67__ every day. Later, engineers ____68___(manage) to construct railways in a system of deep tunnels ( 隧道） , which became known to the tube. This development was only possible with the ___69___ (introduce) of electric-powered engines and lifts. The central London Railway was one of the most ___70___(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.