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.

Q: Fact 1: if an object is black then that object absorbs all visible light. 
Fact 2: Light grains are quartz, Black grains are coal.

A: Coal absorbs all visible light.
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Q: Fact 1: Balance is the ability to sense and maintain body position. 
Fact 2: Another name for sense of body position is proprioception.

A: Balance involves proprioception ability.
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Q: Fact 1: harming an animal species has a negative impact on the population size of that species. 
Fact 2: Hot weather can cause harmful bacterial growth in feeders.

A:
weather can have a negative impact on a species' population size.
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