Answer:
A.Sound waves are unable to travel in outer space.
Answer:
The answer is c
Explanation:
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Answer:
Yes.
Explanation:
If the graph line comes lowers from 1999 to 2013 so it means that steps taken by the EPA and the factories were effective in reducing air pollution. The steps taken by the EPA and the factories were effective in reducing air pollution occurs from two pollutants i. e nitrogen oxides (NOx) and sulfur dioxide (SO2) if they install chimneys which collect these gases and reduce pollution. if the factories uses coal having less concentration of sulphur so less air pollution occurs.