The answer for this question would be Integument, digestive, respiratory and urogenital.
The largest system that contact with the external environment would be integument and digestive. That makes two system has normal flora of microbes and not sterile like the other systems. Normal flora of microbes will prevent the pathogen microbe grows so it gives some benefit.
Automatic stabilizers are any part of the government budget that offsets fluctuations in aggregate demand. They offset fluctuations in demand by reducing taxes and increasing government spending during a recession, and they do the opposite in expansion
Explanation:
The willingness to differentiate among possessing expertise and getting a serious level of respect is ethical competence. While applying policies to promote skill and qualifications to preparation and schooling for skilled careers, it is the phase outside technological competence that ethical competence must always be recognized.
Answer:
I don't know I'm sorry I will tell you another answer asks me
