根据对话内容,从对话后的选项中选出能填入空白处的最佳选项。选项中有一项为多余选项。完成后请将答案写到二卷答题纸上。
The world’s first completely automatic（自动的）railway has been built under the busy streets of London. 1. _______________________________. The new Victoria Line was opened in 1969. This new line was very different from the others.
The stations on the other lines need a lot of workers to sell tickets, and to check and to collect them when people leave the trains. 2. ______________________________. Here a machine checks and collects the tickets, and there are no workers on the platforms at all. On the train, there is only one worker. 3. _____________________. But usually he just starts it; it runs and stops by itself. The trains are controlled by electrical signals which are sent by the so-called command spots. The command spots are the same distance apart. Each sends a certain signal. The train always moves at the speed that the command spots allow. If the command spot sends no signals, the train will stop. 4. _______________. The computers also fix the train speeds, and send the signals to the command spots.
5. ___________________________. Once train may stay too long at a station; the other trains will then automatically move slower.
A. If necessary, this man can drive the train.
B. The railway is called the Victoria Line, and it is part of the complete London underground railway.
C. The computer makes the decision about when to use a gas engine and when to go electric.
D. This is all different on the Victoria Line.
E. Most of the control work is done by computers.
F. Other machines make sure that the trains are always a safe distance apart.
______ _______ ________ _______________