2. Explain what a drug is and why drugs can be addictive.
why is there no answer to this

Which of the following can be effective in preventing the onset of viral infection in humans? a) taking vitaminsb) getting vaccinatedc) taking antibioticsd) taking drugs that inhibit transcription

Active immunity refers to: a. the defenses people are born with. b. temporary immunity granted from another source. c. immunity gained through immunization and exposure to diseases. d. natural immunities that protect humans from other animal diseases

Why do you need two different circuits of blood vessels in your body?