Answer:
D. Two reactants combine to form one product
Explanation:
The definition of synthesis in chemistry is "the production of chemical compounds by reaction from simpler materials."
A is decomposition, B is DOUBLE replacement, and C is SINGLE replacement.
<span>1. Blocks Ultra violet rays that can be harmful.
2. Provides Oxygen, so we can live.
3. It blocks meteors from hitting Earth's surface.
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