Answer: A group that closet matches characteristics
Explanation:
A representative sample is a group that closely matches the characteristics of its population as a whole. In other words, the sample is a fairly accurate reflection of the population from which the sample is drawn.
Answer:
70% solution is more effective
Explanation:
The 70% solution is more effective at inhibiting microbial growth than the 100% solution of the ethyl alcohol.
This is because the pure ethyl alcohol coagulates the protein that is in contact with it.
Also, pure alcohol will tend to evaporate faster than the 70% solution of the ethyl alcohol and it will not be that much effective.
Human and the natural ones can change the ecosystem