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: hearing is used for sensing sound by animals. 
Fact 2: All cats are animals.

A: hearing is used for sensing sound by cats.
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Q: Fact 1: if a planet becomes too hot then that planet cannot sustain life. 
Fact 2: If a planet is too close to a star, then it will be too hot for liquid water to exist.

A: If a planet is too close to a star, that planet cannot sustain life.
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Q: Fact 1: smoking causes direct damage to the lungs. 
Fact 2: Many people smoke cigarettes.

A:
cigarettes cause direct damage to the lungs.
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