寒冷的冬天，可以看到户外的人不断呼出“白气”，这是液化现象，是呼出的气体中的水蒸气液化成的小水珠，小水珠浮于空中形成“白气”．这种现象有时可被人们利用．眼镜片粘附了尘土，看起来变得模模糊糊．这时，可对着眼镜片呵气，就会在眼镜片上凝结一层小水珠，然后擦拭． In the cold winter, you can see people in the open air constantly exhaling “white gas”. This is a phenomenon of liquefaction. It is the small water droplets liquefied by exhaled gas, and the small water droplets float in the air to form “white gas”. This phenomenon can sometimes be used by people. 2. The spectacle lens adhered to dust and looked blurry. At this time, you can breathe into the glasses, it will condense a small layer of water on the lens, and then wipe.