表示副词[on]之义;
例句:
A skeleton staff of 20 is being kept on.
留下了20名骨干人员。
The cold, misty air felt wonderful on his face.
雾蒙蒙,寒冷的空气使他脸上感觉很舒爽。
She planted a kiss on each of his leathery cheeks.
她在他粗糙的面颊上左右各吻了一下。