他一转旋钮，声音就变小了。
As he turned the knob, the sound diminished.

这个电钮接通电流。
This button switches the current on.

你可以按这个按钮叫电梯。
You may push this button to call the elevator.

请你在这件衬衫上钉一颗钮扣好吗？
Will you stitch a button on this shirt?

我用手帕把钮扣擦亮。
I polished my buttons with a handkerchief.

按下这个按钮倒带。
Depress this button to rewind the tape.

按这个按钮开动引擎。
Press this button to start the engine.

你按下这个按钮就可以关机。
You may stop the machine by pushing this button.