老师，请问operating leverage是什么呢？

If central banks want to stimulate growth in periods of deflation, which of the following is a limitation on its ability? A The fact that interest rates have a minimum value (0%). B The interaction of monetary and fiscal policy. C Ricardian equivalence. 老师，A选项日本的利率不是能小于0吗？ B，央行也无法干预财政政策吧？C选项能解释一下吗？

A development country maintains a fixed value for its currency relative to the U.S. dollar. It is experiencing a decline in its economic activity, and its inflation rate falls below the Level in the United States. If the developing country wants to maintain the fixed exchange rate target, its A Money supply will contract. B Short-term interest rates will fall. C Foreign exchange reserves will decrease. 老师，买美元那本国的货币不是减少吗，然而又说要货币宽松，有矛盾吧？

这道题按照单老师教的方法算出来是710，为什么不按照单老师的方法呢。

NX=S-I-(G-T)，既然NX降低，I会升高，(g-t)跟I一样在等式右边的符号为负号，为什么不跟investment一样是升高呢？反而是需要降低？

请问这道题解释的啥，没懂。

这道题讲义中没有提及，请问是在哪里的知识点。

请问这道题货币乘数的公式讲义里没有，怎么推导出来的。

这题能看出违反不独立客观是因为题干中提到了他害怕丢掉工作吗？

听不懂解析