Given a scientific question and its correct answer, generate supporting facts for the answer. This supporting fact can be an explanation for the answer to the given question.

Q: Question: Matter can exist either as a pure substance or as a combination of what? Answer: different substances

A: The properties of matter, both physical and chemical, depend on the substances that matter is made of. Matter can exist either as a pure substance or as a combination of different substances.
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Q: Question: What word describes a molecule that repels polar water? Answer: hydrophobic

A: The other end of each phospholipid molecule is nonpolar and has no electric charge. This end of the phospholipid molecule repels polar water and is described as hydrophobic, or "water hating. ".
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Q: Question: What are commonly used to control insect pests, but can have harmful effects on the environment? Answer: insecticides

A:
Insecticides are commonly used to control insect pests, but they can have harmful effects on the environment.
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