Acid rain is an example

a. a primary pollutant
b. a secondary pollutant
c. a tertiary pollutant
d. none of the above

Which of the following structures is not found in both plant and animal cells? a) chloroplast b) cytoskeleton c) ribosomes d) mitochondria

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

Which of these outcomes is a negative impact of postindustrial societies on the environment? a. nomadic ways b. overpopulation c. overgrazing d. resource renewal