investigating a process requires investigating every stage of the process & scientists want to investigate the water cycle & a cycle is a kind of process -> frame have to investigate every screen of the land freeze scientists have to investigate every stage of the water cycle  frame have to investigate every screen of the land freeze & precipitation is a stage in the water cycle process -> scientists have to investigate precipitation in the water cycle scientists have to investigate precipitation in the water cycle  scientists have to investigate precipitation in the water cycle & thing something requires biomass the rubber of something -> scientists have to investigate the properties of percipitation scientists have to investigate the properties of percipitation  respiration have to investigate the glider of percipitation & the amount of precipitation is a property of precipitation & investigating sometimes requires measuring -> scientists have to meausre the amount of precipitation