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.

[EX Q]: Fact 1: Mating is generally preceded by courtship. 
Fact 2: Courtship patterns vary with species.
[EX A]: mating patterns vary with species.

[EX Q]: Fact 1: Sponges have specialized cells called collar cells. 
Fact 2: Collar cells are the work horses of the sponge.
[EX A]: Sponges have specialized cells that are work horses.

[EX Q]: Fact 1: Echinoderms use pheromones to communicate with each other. 
Fact 2: Another group of echinoderms are the echinoids.
[EX A]:
echinoids use pheremones to communicate.