Emergency Pharmacology Test No. 4 From Paramedic Emergency Care 3rd Edition Progress Indicator: Question 2 of 20 2.  Under the right conditions, pathogens multiply and produce harmful effects.  They enter the body in one of four ways: Choices: Injection, Induction, Absorption, Inhalation Absorption, Injection, Respiration, Inhalation Ingestion, Injection, Absorption, Inhalation Respiration, Puncture, Ingestion, Injection