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: Mollusks live in most terrestrial, freshwater, and marine habitats. 
Fact 2: Clams, oysters and snails are familiar mollusks.
Example Output: oysters live in most terrestrial, freshwater, and marine habitats.

Example Input: Fact 1: HIV infects and destroys helper T cells. 
Fact 2: T-helper cells are lymphocytes.
Example Output: HIV infects and destroys lymphocytes.

Example Input: Fact 1: sound can be used for communication by animals. 
Fact 2: Animals use sound in sophisticated ways.
Example Output:
animal communication is sophisticated.