1. It first infects you because you breathe in some of the infectious agents. 只要吸入病原体，你就会被感染。
2. For the most part, however, we breathe in the aromas which surround us without being consciously aware of their importance to us. 然而，在大多数时候，我们呼吸着周围的香气，却没有意识到它们对我们的重要性。
3. When there's a fire, follow the teachers' instructions, leave the classroom quickly and use a piece of cloth to cover your mouth and nose so that you don't breathe in smoke. 发生火灾时，按照老师的指示，迅速离开教室，用一块布遮住口鼻，以免吸入烟雾。
4. In smoggy weather, the machine would breathe in the air in front of the bike and blow out a stream of clean air toward the biker's face. 在有雾霾的天气里，机器会吸进自行车前面的空气，然后向骑自行车的人的脸上吹出一股清新的空气。
5. O Sit outside and breathe in the air. 坐在室外，呼吸新鲜空气。
