Answer:B
Step-by-step explanation:
Answer;
D.
Coal-fired stoves, factories, and power plants
Explanation;
-Air pollution from factories and coal-fired power plants includes sulfur dioxide, nitrogen oxides, particulate matter (PM), and heavy metals, leading to smog, acid rain, toxins in the environment, and numerous respiratory, cardiovascular, and cerebrovascular effects.
There's no "why" because it isn't.
The greatest common factor of two numbers
is only even when the two numbers are even.
==> The greatest common factor of '14' and '21' is ' 7 ' .
If you know that 5*6=30 then you know that the answer will be more than 30. So now you have to just add 6 to the number 30 three more times to get the answer that 8*6=48
