What has caused most of the natural plant life in the american midwest to vanish rain fall amounts decreased in region grass fires destroyed much of the vegetation trees and shrubs replaced the vegetation farmers plowed the land to plant crops not this on ; )

Suggest two reasons why irrigation is important for human development of the desert (4 marks)

The us and canadian governments are doing all of the following to combat environmental problems except a. encouraging the use of public transportation b. enacting clean water policies c. requiring emissions testing d. limiting animal populations in some regions

Name the three types of population distribution