tap-tap

He gave a tap at the microphone before speaking.

他在讲话前先一下扩音器。

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

我们有巨大的石油矿藏在待开发。

Blade tools: eyebolt, turning tool, Allen key, screw tap, milling cutter, drill bits, etc.

埃令螺丝（吊环）、圆车刀、六角匙、丝攻、铣刀、钻咀。

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之后，仍然不断有坏消息传出。