precipitation
名词 precipitation:
the quantity of water falling to earth at a specific place within a specified period of time
the process of forming a chemical precipitate
the falling to earth of any form of water (rain or snow or hail or sleet or mist)
同义词:downfall
the act of casting down or falling headlong from a height
an unexpected acceleration or hastening
overly eager speed (and possible carelessness)
同义词:haste, hastiness, hurry, hurriedness