Paragraph 4 of the passage serves mainly to do which of the following? A. Show the progress of desertification down through history B. Propose a method for dealing with the desertification p
Paragraph 4 of the passage serves mainly to do which of the following?
A. Show the progress of desertification down through history
B. Propose a method for dealing with the desertification problem.
C. Describe one process that leads to desertification
D. Describe the main cause of desertification in one particular area