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.

Example Input: Fact 1: hearing is used for sensing sound by animals. 
Fact 2: An ear improves hearing.
Example Output: Most animals have ears.

Example Input: Fact 1: Viruses are usually considered to be nonliving. 
Fact 2: Humans acquire the infection from contact with infected animals, carcasses, or nonliving material.
Example Output: Viruses are usually acquired from contact with infected animals.

Example Input: Fact 1: sunlight and rain can cause a rainbow. 
Fact 2: Rain water contains small particulates and acid.
Example Output:
Sunlight and water containing small particulates and acid can cause a rainbow.