Combine the given two facts to write a concluding fact. Note that there should be some parts of the first and second facts that are not mentioned in this conclusion fact. Your combined fact should be the result of a chain between the two facts. Chains form when two facts connect together to produce a concluding fact. An example of a chain is: "pesticides cause pollution" (fact1) + "pollution can harm animals" (fact2) → "pesticides can harm animals" (conclusion fact). Parts of the concluding fact overlap with the first and the second fact. To construct such a  concluding fact, a useful way is to borrow the subject from one fact and the ending conclusions from another fact.

Fact 1: freezing means changing from a liquid into a solid by reducing heat energy. 
Fact 2: Ice is a cold frozen liquid.
Ice is made from reducing heat energy.

Fact 1: hydropower requires damming a river. 
Fact 2: Hydropower is a renewable resource.
Damming a river can provide a renewable resource.

Fact 1: water vapor condensing in clouds causes rain. 
Fact 2: If the cooling is sufficient, water vapor condenses into clouds.

Water vapors turn into clouds and rain when it's cool.