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: Viruses cannot reproduce by themselves. 
Fact 2: Viruses include the Tobacco Mosaic Virus.
Example Output: The Tobacco Mosaic Virus cannot reproduce by itself.

Example Input: Fact 1: condensation causes clouds to form. 
Fact 2: Fog is a cloud that forms on the ground.
Example Output: condensation causes fog.

Example Input: Fact 1: Flowing water can slowly dissolve carbon in sedimentary rock. 
Fact 2: Rivers are long flowing waters.
Example Output:
rivers can slowly dissolve carbon in sedimentary rock.