I believe that the answer you're looking for is Water.
Heat from the Sun causes water to evaporate from the surface of lakes and oceans. This turns the liquid water into water vapor in the atmosphere. Plants, too, help water get into the atmosphere through a process called transpiration!
The main component in three investigations is that in my opinion The common denominator of the fact that they are all three still investigations.
An interaction in which one organism kills and eats another is called predation.
