tap-tap

He gave a tap at the microphone before speaking.

他在讲话前先轻叩了一下扩音器。

We have enormous reserves of oil still waiting to be tapped.

我们有石油矿藏在等待开发。

Eight hours after the market had closed, the tickertape machines were still tapping out the bad news.

股票市场关闭八个小时后，仍然不断有坏消息传出。