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: gravity causes objects that have mass to be pulled down on a planet. 
Fact 2: Weight is the measurment of the force of gravity on a mass.

SOLUTION: Weight is measured when objects are pulled down by gravity.

PROBLEM: Fact 1: Humans have collected and grown mushrooms for food for thousands of years. 
Fact 2: Foods rich in chlorine are mushrooms, parsley, sweet potato, rhubarb, and especially tomato.

SOLUTION: Humans have collected and grown foods rich in chlorine for thousands of years.

PROBLEM: Fact 1: All plants have a characteristic life cycle that includes alternation of generations. 
Fact 2: Alternation of generations always includes a sexual phase alternating with an asexual phase.

SOLUTION:
All plants have a characteristic life cycle that includes sexual and asexual reproduction.