(Question)
Q: What type of contamination causes almost 90% of diarrheal disease worldwide? Choices: - air contamination - ground contamination - food contamination - water supply contamination A:
(Answer)
water supply contamination

(Question)
Q: The structure of the gas carbon dioxide consists of one atom of carbon and two atoms of what? Choices: - sulfur - methane - Helium - oxygen A:
(Answer)
oxygen

(Question)
Q: What is given off from plants and taken in by animals? Choices: - methane - sulfur - nitrogen - oxygen A:
(Answer)
oxygen