To avoid being digested by their host, endoparasites have a thick protective covering called the
a. cell wall.
c. protoplasm.
b. cilia.
d. tegument.

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