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: Light enters the eye through an opening called the pupil. 
Fact 2: Just behind the pupil is a lens.
Example Output: light enters the eye through an opening just in front of the lens.

Example Input: Fact 1: Plasma cells are activated B cells that secrete antibodies. 
Fact 2: Antibodies are produced by plasma cells.
Example Output: activated B cells secrete antibodies.

Example Input: Fact 1: rocks interacting with wind over long periods of time causes weathering. 
Fact 2: Weathered rock is called saprolite .
Example Output:
rocks interacting with wind over long periods of time causes saprolite.