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.

Fact 1: glass cause refraction of light. 
Fact 2: Refraction Refraction is the bending of light rays.
Glass causes bending of light rays.

Fact 1: Courtship is behavior that is intended to attract a mate. 
Fact 2: Almost all animals display colors to attract a mate or to scare off a predator.
Courtship can be manifested by displays of color.

Fact 1: protein is used to repair cells by the human body. 
Fact 2: Protein Protein is needed for tissue maintenance and repair.

protein repairs cells.