tap-tap

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

我们有巨大的石油矿藏在等待开发。

He gave a tap at the microphone before speaking.

他在讲话前先轻叩了一下扩音。

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

市场关闭八个小时后，仍然不断有坏消。