Hot air
01
空话, 大话
a statement that is untrue, exaggerated, or meaningless
例子
Do n't pay attention to his boasting; it 's just hot air without any real achievements to back it up.
别在意他的吹嘘；那只是空话，没有任何实际成就来支持。
02
热空气, 加热的空气
air made hot, causing it to lift
例子
Hot air rises, which is why chimneys work efficiently.
热空气上升，这就是为什么烟囱能高效工作。
