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.

Input: Consider Input: Fact 1: a plant requires water to grow. 
Fact 2: Clouds form by the condensation of water vapor.

Output: a plant requires Clouds to grow.


Input: Consider Input: Fact 1: hearing is used for sensing sound by animals. 
Fact 2: All cats are animals.

Output: hearing is used for sensing sound by cats.


Input: Consider Input: Fact 1: Most hormones are regulated by feedback mechanisms. 
Fact 2: Control is better described as regulation.


Output: Most hormones are controlled by feedback mechanisms.