instruction:
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.
question:
Fact 1: Protozoa make humans sick when they become human parasites. 
Fact 2: Malaria parasites are transmitted by mosquitos.
answer:
Malaria is a protozoa that make humans sick.


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


question:
Fact 1: Any antigen that causes an allergy is called an allergen. 
Fact 2: Antigens are proteins foreign to the body.
answer:

Any foreign protein that causes an allergic reaction is called an allergen.