Cameron was given the following series of observations. which represents a theory?
rocks are found on the ocean floor.
rocks can form volcanoes.
rocks break down over time.
certain types of rocks form deep inside earth.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

explanation:

on disadvantage of hydroelectric power is the cost. another disadvantage of using hydroelectric power is finding a water source powerful enough to harvest hydroelectric power.