Genetics explain why you look like your father and if you don't why you should. We say the cause of perfume disappearing is evaporation. Evaporation get blamed for a lot of things people forget to put the top on. Water vapor gets together in a cloud. When it is big enough to be called a drop, it does.
Humidity is the experience of looking for air and finding water.
Rain is often known as soft water, oppositely known as hail. Rain is saved up in cloud banks. In some rocks you can find the fossil footprints of fishes. Cyanide is so poisonous that one drop of it on a dogs tongue will kill the strongest man. A monsoon is a French gentleman.