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.

Ex Input:
Fact 1: hearing is used for sensing sound by animals. 
Fact 2: Sound waves enter the ear, and are then amplified.

Ex Output:
Animals use ears to hear.


Ex Input:
Fact 1: pollutants have a negative impact on the environment. 
Fact 2: Environment and Health Environment and Health All living things depend on their environment.

Ex Output:
pollutants have a negative impact on all living things.


Ex Input:
Fact 1: water vapor cooling causes that water vapor to condense. 
Fact 2: When water vapor cools, it condenses to form clouds.

Ex Output:

Clouds are formed when vapor cools.