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: fluoride decreases tooth decay. 
Fact 2: Humans get most of their fluoride in drinking water.
Example Output: Drinking water decreases tooth decay.

Example Input: Fact 1: landfills have a negative impact on the environment. 
Fact 2: An ecosystem is an environment and all the members of that environment.
Example Output: Landfills have a negative impact on the ecosystems.

Example Input: Fact 1: Temperature falls from lower to higher altitudes. 
Fact 2: Temperature Temperature is recorded in degrees Celcius.
Example Output:
degrees celcius falls from lower to higher altitudes.