Passage comprehension I-22[音频]
A. The workers on the underground platforms were replaced by machines
B. It became the first completely automatic railway in the world.
C. A completely automatic line was added to its network.
D. Its trains became computer-controlled.
查看答案
Passage comprehension I-23
A. The platform workers.
B. The computers.
C. The command spots.
D. The machines.
Passage comprehension I-24
A. To drive the train after it started automatically.
B. To start the train and to drive it when necessary.
C. To take care of the passengers on the train.
D. To send commanding signals to the command spot,
Passage comprehension I-24
A. It will stop automatically.
B. It will move on at the same speed.
C. It will gradually slow down
D. It will keep a safe distance from the other trains
以下选项属于Spark中的行动(Action)操作的是？（ ）
A. filter()
B. map()
C. reduce()
D. reduceByKey()
微信支付 
支付宝支付