What can be a major threat to health?
bicycling using a car smoking skateboarding viruses Dehydration influenza doctors
A B C D E F G H
Air pollution Air pollution is a major threat to health.
Using a car can be a major threat to health.
What can be a major threat to health? (A) bicycling (B) using a car (C) smoking (D) skateboarding (E) viruses (F) Dehydration (G) influenza (H) doctors