Fact 1: Abreathing mask is used for keeping harmful particles from entering the respiratory system. Fact 2: Another respiratory defense is the immune system. Given the two facts above, answer the question "the what is a defense against harmful particles from entering the body" with the following options: - lungs - It remains dormant - A virus - immune system - exoskeleton - pancreas - chickenpox - liver
The answer to this question is:
immune system