Aerosol insecticide is usually used in summer, which compresses the volume at room temperature, allowing gas to enter something and fill the variety.

There are two methods to liquefy (1) gas: compressing the volume and lowering the temperature;

At room temperature, the gas is liquefied into liquid by compressing the volume and stored in a metal bottle to fill the aerosol insecticide.

(2) After spraying pesticides for a period of time, metal cans will feel cold. This is because after spraying the pesticide, the liquid medicine in the tank will quickly vaporize into gas, which will absorb heat and reduce the temperature of the metal tank, so it will cool down.

So the answer is: compress the volume; Liquefaction; evaporate