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: cutting down trees has a negative impact on an ecosystem. 
Fact 2: Ecosystems are living communities.

Ex Output:
Cutting down trees has a negative impact on living communities.


Ex Input:
Fact 1: a stopwatch is used to measure time. 
Fact 2: Timing is the essence of punctuality.

Ex Output:

a stopwatch is used to help people be punctual.