经典人文频道每天四档播出。

Classical Humanities channel broadcast a day fourth gear.

四档变速箱的轴承有25%的时间受载。

On a four-speed box the bearings are under load 25% of the time.

变速箱采用常啮斜齿轮传动，结合套换档、双杆机械操纵，前进五档、后退四档。

Transmission : normally meshed helical gear drive, coupling sleeve shift and two lever operation. The transmission has five forward speeds and four backward speeds .

我注意到她打在二档上，通常这种状况应是三档或四档，于是我告诉她该如此如此。

I noticed that she was keeping the car in second gear when she clearly should have shifted to third, maybe even to fourth. Stupidly, I told her so.