dirty——clean People and animals need clean air to breathe. 人和动物都需要清洁的空气来呼吸. cold——hot You look hot and tired. 你看起来很热也很累. wet——dry Today we talk about how to stay warm,dry and safe. 今天我们来讨论一下如何保温、保持干燥和安全. near——far It is not far,it is within reach. 它并不遥远,它是可以到达的.