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: a mold spore has a negative impact on the respiratory system. 
Fact 2: Insects also have both a heart and a respiratory, or breathing, system.

SOLUTION: a mold spore has a negative impact on breathing.

PROBLEM: Fact 1: Insects may live in large colonies and have complex social behaviors. 
Fact 2: Ants and butterflies are insects.

SOLUTION: ants may live in large colonies.

PROBLEM: Fact 1: gases from burning coal and oil dissolving in water in the atmosphere causes acid rain. 
Fact 2: Acid rain comes from polluted clouds.

SOLUTION:
Gases from burning coal and oil dissolving in water in the atmosphere causes polluted rain.