问题如下：
The IS curve shows the relationship between
选项：
A.real interest rates and real aggregate income, and is positively sloped.
B.real interest rates and real spending amount, and is negatively sloped.
C.real interest rates and real aggregate income, and is negatively sloped.
解释：
C is correct.
The IS curve illustrates the negative relationship between real interest rates and real aggregate income. Investment (I) and savings (S) are the primary variables that adjust to maintain the balance between expenditure and income
考点：IS
解析：IS曲线说明了实际利率与实际总收入之间的负相关关系。投资(I)和储蓄(S)是调维持收支平衡的主要调整变量。所以只有C选项正确。
老师，为什么B不对呀，总支出不是等于总收入吗？
