Definition: the mixture of gases which surrounds the Earth and which we breathe Level: A2
我喜欢新鲜空气。
I like fresh ___air.
城市里的空气常常被污染，而乡村的空气则清新得多。
The ___air in cities is often polluted, while that in the countryside is much fresher.
早上的空气特别清新。
The morning ___air feels especially fresh.
