The answer would be Class system. The class system in social studies setting refers to the system to decide social rank that based on accomplishment and personal merits.
The status that Kelly's family get in the society is based on their diligent work in taking care of the merchant auto business.
Answer:
Aerobic
Explanation:
Aerobic exercises make the muscle use oxygen in it's operation.
Natural environment has the ability to gather some pollutants yet if too much then the environment could no longer handle it. A leaky sewage can pollute an aquifer with I. arsenic as the contaminant. Arsenic is a metalloid existing in the Earth's crush. Exposure is natural yet can be aggravated by the human activities.