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
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 progress that leads to desertification.