... Grade 12 UNIT 9: DESERTS THE SECOND SEMESTER 25 We _drive fast; we have plenty of time A can't B needn't ... use firewood, raise animals, and grow crops in order to live Page THE SECOND SEMESTER Grade 12 UNIT 9: DESERTS THE SECOND SEMESTER Humans can make deserts, but humans can also prevent their growth ... is called "desertification" This term started being (46) _ in the 195 0s The idea of desertification was first known in the 193 0s Much of the Great Plains grew very dry (47) a result of drought...