定期航班的数量正让空中交通指挥系统不堪重负。The volume of scheduled flights is straining the air traffic control system.空中救援行动的规模现在已经有所缩小。The air rescue operation has now been scaled down.他们需要等空中交通管制人员的放行。They have to wait for clearance from ...
The oven has an automatic timer and other refinements.这个烤箱有自动定时器及其他改进装置.The heater is on a timer switch.加热器连在一个定时开关上。He flipped the timer switch.他按了一下定时开关。The timer must have been actuated by radio control.这个定时器肯定是无线电操纵开...