Which of the following human activities would be expected to be the biggest contributor to air pollution?
a. driving
b. restaurant garbage
c. aerosol cans
d. nuclear weapons

What is difference between an epidemic and a pandemic? a) an epidemic is a disease; a pandemic is a treatment.b) an epidemic is restricted to a local region; a pandemic is global.c) an epidemic has low mortality; a pandemic has higher mortality.d) an epidemic is caused by a bacterial infection; a pandemic is caused by a viral infection.