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.
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Question: 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.

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


Question: Fact 1: having food has a positive impact on an organism 's health. 
Fact 2: Animals eat plants for food.

Answer: Eating plants has a positive impact on the health of animals.


Question: Fact 1: navigation requires knowing direction. 
Fact 2: Sailing ships navigate the waters.

Answer:
sailing ships require knowing direction.