The answer is everything you just said in the question and thank you very much for th 50 points i am so grateful . kissess goes to you
I believe the answer is:
random sample of the town's population
A mix of participants that reflect your town's makeup
Random sample is needed in order to ensure that the researchers do not obtain only the subjects that is close to them. Mix of participants is needed in order to ensure that the sample population are not taken from group with close similarties in behaviour.
Earth's earliest atmosphere lacks Oxygen, the gas necessary for life because it is a requirement for aerobic respiration.Oxygen does so many things for our body but It is the only respiration human body cells are capable of. Oxygen is needed for multiple reasons. It nourishes cells, allows the chemical transportation, helps toxins and waste material to break down and it supports and provides energy to our metabolism.
Bartering is trading, in today's society we buy and sell using currenxy