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: wind causes erosion. 
Fact 2: Erosion is the physical removal of rock particles.

A: Wind causes the removal of rock particles.
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Q: Fact 1: skin is used for protecting the body from harmful substances. 
Fact 2: Contamination is the unintended presence of harmful substances or microorganisms in food.

A: The skin is used for protecting the body from contamination.
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Q: Fact 1: a mutation in the sex cells of a parent can cause a new trait to appear in the parent 's offspring. 
Fact 2: An adaptive trait helps an organism survive in a particular environment.

A:
mutation in the sex cells of a parent can help the offspring survive.
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