一、课前自主预习——课文重建
根据本单元reading 课文在下面短文空格中填入所缺单词（每空一词）。
The London underground system has the 1._________ of being the oldest and most complex underground system in the world. Rail services to London were first developed during the first half of the 19th century, but people couldn’t build railways into the city because doing that could cause great 2._________ to many old buildings. Therefore, the number of vehicles on the road used to 3._________ people to and around the city centre caused unbelievable traffic jams. This traffic problem led to the 4.__________ of the underground system.
In 1854, the British government gave 5._________ to the construction of an underground railway in the centre of London. the 6.________ tunnels were opened in 1863. In 1884, two companies linked up and 7.________ underground service in the middle of the city. Because of the smoke from the steam engines, early underground lines needed large holes leading to the surface at regular 8.________.
The first railway tunnel under the River Thames was dug in 1884. The City and South London Railway opened the first 9.____ underground railway in 1890. Over the next twenty –five years, six independent deep underground lines were constructed. The underground system has some unusual uses during World War II and it is working to 10.________ huge numbers of people as it has done for many years.
