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: absorbing sunlight causes objects to heat. 
Fact 2: Heat can harm the camera and the film.
Sunlight can harm a camera and film.

Fact 1: Veins generally carry deoxygenated blood. 
Fact 2: Blood carries blood cells.
Veins carry cells.

Fact 1: Most hormones are regulated by feedback mechanisms. 
Fact 2: Much hormonal regulation depends on feedback loops to maintain balance and homeostasis.

Hormones maintain balance with feedback loops.