问题详情

What do we learn about deserts from this text？
A．Deserts can change into green and fertile areas.
B．Certain areas have always been desert.
C．Deserts were once the home of elephants and giraffes.
D．Deserts have been growing since the beginning of the world.此题为多项选择题。请帮忙给出正确答案和分析，谢谢！