What are the problems the U.S. economy has faced from time to ti

What are the problems the U.S. economy has faced from time to time?
A、Recessions.
B、Depressions.
C、Inflation.
D、All of the above.
【正确答案】：D
【题目解析】：美国经济时不时面临的问题是衰退，凹陷，通货膨胀。