问题详情

What is the main purpose of the talk？

A．To show what happens after an economy has experienced a boom-and-bust cycle

B．To illustrate the conditions needed to produce a boom-and-bust cycle

C．To demonstrate how boom-and-bust cycles have changed over time

D．To explain why the boom-and-bust cycle is not a frequent historical occurrence

此题为多项选择题。请帮忙给出正确答案和分析，谢谢！