上齿轮

The teeth on the gears mesh as they turn round.

转时齿轮上的齿与齿。

The statue of General Sedgwick, cast from cannons captured by the VI Corps which he commanded during the Civil War, has rowel spurs that turn.

塞吉维克的塑像由一门他在内战中领导的六团缴获的大炮浇铸成，周围是马刺上的小齿轮。