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: when a plant grows , the size of the leaves of that plant may increase. 
Fact 2: Leaves are the main sites of photosynthesis.
Example Output: when a plant grows the main site of photosynthesis increases in size.

Example Input: Fact 1: Viruses are not cells at all, so they are neither prokaryotes nor eukaryotes. 
Fact 2: Viruses Viruses are the smallest agents of disease.
Example Output: The smallest agents of disease are not cells at all, so they are neither prokaryotes nor eukaryotes.

Example Input: Fact 1: preventing the transfer of heat from an organims 's body causes that organism to keep warm. 
Fact 2: Animals are organisms that have ingestive metabolism.
Example Output:
Preventing the transfer of heat from an animal 's body causes that animal to keep warm.