1. Vapor or fumes may condense on piping, ducts, or stack walls. 蒸气或尘雾可能在管道，烟道或烟囱壁上冷凝。
2. When an aroma is sensed, the molecules from the vapor interact with numerous receptors, causing them to send a signal to the brain. 当某种气味被感觉到时，来自蒸气的分子与为数众多的感官相互作用，导致它们将信号送到大脑。
3. As the planet approached its current size, however, its gravitation became strong enough to hold gases and water vapor around it as an atmosphere. 然而，当行星接近现在的大小的时候，它的重力强到了足以保持其周围的气体和水蒸气来形成大气层。
英英解释
n.
1. a visible suspension in the air of particles of some substance
2. the process of becoming a vapor
