单项选择题
The Channel Tunnel(海底隧道), to be opened officially by British Queen Elizabeth II and French President Francois Mitterrand on March 8, links(连接) British and France for the first time since the Ice Age. The project spent eight years completing and cost an estimated(估计)$13.5 billion. The channel is considered an engineering wonder of the 20th century. Le Shuttle is the channel’s specially built train. The total journey time between Calais, France and Folkstone Britain is 35 minutes. The service is scheduled to run 24 hours a day, seven days a week in both directions.
The Channel Tunnel is considered as a wonder because(). A. it took nearly a hundred years to complete this project
B. there have been so many difficulties in this great project
C. it has shortened the journey very much
D. the tunnel will be opened by both the queen and the president