监视发动机机械状况的参数仪表有:().
A.EGT,FF,EPR
B.增压比,膨胀比
C.扭矩
D.滑油压力,温度,转速,振动
参考答案:D
You’d better ______ football in the street.
A.not play
B.playing
C.not to play
D.play
什么是紫外线、红外线?