Examples:
Respiratory System, (I think) Organ System, Circulatory System, Nervous System, etc.
Cigarette smoking and environmental chemicals
Tobacco smoke and certain environmental chemicals are known carcinogens (substances that can cause cancer in living tissue). The tobacco smoke from cigarette smoking contains harmful chemicals such as hydrogen cyanide, arsenic, ammonia, benzene, and many more. In fact, from 2009 to 2013, three out of 10 cancer deaths in the U.S have been attributed to cigarette smoking or exposure to tobacco smoke.
If a population of rabbits is introduced to a population of dandelions the rabbits will end up eating all the dandelions
The answer would be combined statistical area. This is made of metropolitan and micropolitan statistical area which would be located in the United States as well as Puerto Rico that demonstrate both economic as well as social linkage.Hope this is the right answer.
