問題詳情：
根據短文內容，從短文後的選項中選出能填入空白處的最佳選項，選項中有兩項爲多餘選項。
The world's first underground(地鐵) was built in London in 1863，At the time，the government was looking for a way to reduce traffic e were so many people living in the poor areas of the city.__1__ If people had an easy way to get to and from work, they would live outside of the city and this would help reduce traffic problems in a result, the idea of the London Underground was born.
The plans for building the London Underground met with several problems. __2_ A steam train pulled the cars along the first underground track which was six kilometers long.__3__ They were treated to comfortable seats inside the cars. However, the smoke from the engine(發動機) soon filled the air in the tunnels(隧道). _4__ Even with its problems, riding the underground did become carried nine million riders in its first year.
Modern underground has come a long way since the early days of the London Underground. __5_ Shopping malls built in traffic stations have helped the popularity of the days many stations include underground department stores, supermarkets and pers never have to go above ground!
A．But the first track was finally opened in January,1863.
B．It is not easy to build the underground.
C．About 30,000 people got on the underground the first day.
D．Sometimes there are not enough seats for the passengers during rush hours.
E．Fans had to be put in the tunnels later to keep the air clean enough for people to breathe.
F．Today there are more than one hundred underground systems around the world.
G．So the officials decided to make it possible for workers to live outside of London and travel easily to work each day.
【回答】
1G 2A 3C 4E 5F
知識點：補充句子
題型：閱讀填空
