1. They located the right chimney by tapping at the walls and listening for the man´s cries.
    他们通过叫击烟囱倾叫声而确定传出声音的那个烟囱。

2. A sound made by tapping on the hull of a ship will be reflected from the sea bottom,
    通过敲击空船发出的声音将会从海底反射回来。

3. Imagine a few people sitting in a waiting room: one is tapping his fingers on his briefcase, another keeps rubbing his hands together, another is biting his fingernails, still another grabs the arms of his chair tightly and one keeps running his fing
    想象一下几个坐在一间等候室里的人：一个在用手指轻轻敲打公文包，一个在不停地揉搓双手，另一个在咬自己的手指甲，还有一个用手紧抓着椅子的扶手，又一个在不断地用手指梳理着头发。