TASK DEFINITION: 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.
PROBLEM: Fact 1: TRH stimulates the pituitary gland to produce thyroid-stimulating hormone, or TSH. 
Fact 2: TRH synthesis is regulated directly by thyroid hormones.

SOLUTION: TSH is regulated by the pituitary gland.

PROBLEM: Fact 1: a planet rotating causes cycles of day and night on that planet. 
Fact 2: Rotation determines day and night, and the length of the day.

SOLUTION: a planet's rotation is what causes night.

PROBLEM: Fact 1: if an object is kicked then force is exerted on that object. 
Fact 2: Kicked Ball A kicked ball is one struck by a player's foot, or leg below the knee.

SOLUTION:
If an object is struck by a foot, then force is exerted on that object.