What are three defense systems and what are the key elements of each?

What are the bodies 3 lines of defense?

The human body has three primary lines of defense to fight against foreign invaders, including viruses, bacteria, and fungi. The immune system's three lines of defense include physical and chemical barriers, non-specific innate responses, and specific adaptive responses.

Explanation:

bro its on g.o.o.g.l.e

i think it can have both positive and negative effects on businesses.

for example:

lets say you own a small business and taxes go up 4% that means it is going to cost your business more money to buy product to sell. but at the same time you make more money from the tax rise.

that is my theory.

answer: uh,crime?

explanation: cause im on probation