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: rocks interacting with wind over long periods of time causes weathering. 
Fact 2: Rocks weather at different rates.
Example Output: wind affects rocks.

Example Input: Fact 1: increasing heat causes thermal expansion. 
Fact 2: Motion helps to increase body heat.
Example Output: motion causes thermal expansion.

Example Input: Fact 1: Sweat wets the skin, and when it evaporates, it cools the body. 
Fact 2: Sweat is released from sweat glands beneath the skin, and as it evaporates, the skin is cooled.
Example Output:
skin is cooled by evaporation.