Fact 1: Viruses often infect bacteria.

Fact 2: Antibiotics kill the good bacteria along with the bad bacteria.

Given the two facts above, answer the question "Viruses often infect something killed by what?" with the following options: 
- Rocks
 - Antibiotics
 - radiation
 - Needle
 - Water
 - Pesticides
 - sun's heat
 - Cooking


 

  Antibiotics       