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: a glacier causes mechanical weathering. 
Fact 2: Mechanical weathering produces detritus.
Example Output: A glacier can produce detritus.

Example Input: Fact 1: boulders are formed by glaciers melting sometimes. 
Fact 2: Glaciers are made of snow, ice and rock.
Example Output: boulders are formed by snow, ice, and rock melting sometimes.

Example Input: Fact 1: Playing is one way mammals and other animals learn how to behave. 
Fact 2: Cats are Mammals that Shed Dogs are Mammals that Wag their tails.
Example Output:
Playing is one way cats learn how to behave.