Degrades the quality of water for drinking, wildlife, and the land surrounding streams
"In republics, citizens have less direct control over government. ... (c) Why do some people hold that the United States is more properly called a republic rather than a democracy? In a Democracy there is no need for a Constitution, since the majority can simply change Law at a whim."
From google
Well if you mean what does the controlled part of a scientific investigation, it is the part of the investigation that will be your control or your base, untouched, original, data and such.
I already helped but
1) C
2) B
3) D
4) A
5) F
6) E
