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: 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: a prism is used for refracting light. 
Fact 2: Refraction is the bending of a ray of light.

Output: A prism can be used to bend a ray of light.


Input: Consider Input: Fact 1: fog is formed by water vapor condensing in the air. 
Fact 2: Fog, by definition, is a cloud that touches the ground.


Output: A cloud of water vapor that condenses in the air but that can sometimes reach to the ground.