1. The water cycle is the path that all water follows as it moves around our planet. Heat from the sun causes water to evaporate from oceans, lakes and streams. Evaporation occurs when water on Earth's surface turns into water vapor in our atmosphere. Warm water rises

A. to instruct
B. to inform
C. to describe
D. to give causes and reasons

2.Some objects may sink and other just float It depends on the density of the object. An object is made of substances that are themselves made up of molecules Density is s easure of both how massive those molecules are, and how closely packed together they are. If the object's total density is greater than that of water, it sinks, but if it is less, it floats Human activity is the main cause of climate change. People bum fossil fuels and convert land from forests to agriculture. Burning fossil fuels produces carbon dioxide, a greenhouse gas. It is called a greenhouse gas because it produces a "greenhouse effect

A.to instruct
B.to inform
C.to describe
D.to give causes and reasons
​