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.

[Q]: Fact 1: Behaviors can be learned through play. 
Fact 2: Cognitive behavior is the behavior of understanding.
[A]: play is cognitive.


[Q]: Fact 1: Loss of ozone has created an ozone hole over Antarctica. 
Fact 2: ClO is the reactive form of chlorine that triggers ozone loss.
[A]: ClO triggers ozone holes.


[Q]: Fact 1: threatening behavior by predators causes a porcupine to extend its quills. 
Fact 2: Porcupine quills can be extraordinarily painful.
[A]:
threatening behavior can be painful.