According to the World Health Organization, one in every _____ persons lives in urban areas with air that is unhealthy to breathe.
a. two
b. six
c. ten
d. twenty
e. fifty
Answer: B
According to the World Health Organization, one in every _____ persons lives in urban areas with air that is unhealthy to breathe.
a. two
b. six
c. ten
d. twenty
e. fifty
Answer: B