A variety of different______(控制系统) are used to accomplish this, ranging from simple clockwork mechanisms to sophisticated computerized control and coordination systems that self-adjust to minimize delay to people using the road.
查看答案
Aside from movable parts, ________ (电气继电器) are also used.
However, with________(计算机交通管制), traffc flows much faster.
By reducing the number of_________(交通拥堵), it reduces the pollution caused by cars.
The computer system not only controls the three thousand traffc lights in London, but it also flashes messages on___________ (电子告示牌) along the roads.