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: Some parasites kill their host, but most do not. 
Fact 2: Tapeworms are internal parasites of vertebrates.
Example Output: most tapeworms do not kill their host.

Example Input: Fact 1: zinc has a positive impact on the healing of wounds. 
Fact 2: Sources of zinc are soil, zinc oxide, zinc sulfate, zinc chelate.
Example Output: soil can have a positive impact on the healing of wounds.

Example Input: Fact 1: volcanic ash in the atmosphere decreases the temperature by blocking the sun. 
Fact 2: With increasing cloud blocking the sun, temperatures drop considerably.
Example Output:
Volcanic ash in the atmosphere increases clouds which block the sun.