In the classification of matter, how would we classify air?
a) pure mixture
b) pure substance
c) homogeneous mixture
d) heterogeneous mixture

Which of these is an example of land degradation? a. containers designed to store pollutants leak. b. fertilizers provide too many nutrients to crops. c. garbage is buried so the land can be reclaimed later. d. a drought kills all the plants in an area, leaving bare land