为什么净出口(X-M)减少会导致政府赤字（G-T）增加？

NO.PZ2016010801000053 问题如下 All else equal, whiof the following wnot a factor to increase the government ficit? A.increase in the excess of private saving over private investment. B.increase in net export. C.a increase in tra ficit B is correct.The fiscbalanequation is given as: (G-T)=(S-I)-(X-M), increase in government ficit (G-T) is a combination of increase in private saving over private investing (S-I) ana crease of tra ficit or net export (X-M).考点Relationship between Income ApproanExpenture Approach解析 财政平衡方程为:(G-T)=(S-I)-(X-M)，政府赤字(G-T)的增加的同时，私人储蓄增加超过私人投资(S-I)，或者贸易赤字或净出口(X-M)减少，所以AC不入选，B入选。 按照解析的思路“财政平衡方程为:(G-T)=(S-I)-(X-M)，政府赤字(G-T)的增加的同时，私人储蓄增加超过私人投资(S-I)，或者贸易赤字或净出口(X-M)减少”c为“tra ficit增加”，所以是not a factor？

NO.PZ2016010801000053问题如下All else equal, whiof the following wnot a factor to increase the government ficit?A.increase in the excess of private saving over private investment.B.increase in net export.C.a increase in tra ficit B is correct.The fiscbalanequation is given as: (G-T)=(S-I)-(X-M), increase in government ficit (G-T) is a combination of increase in private saving over private investing (S-I) ana crease of tra ficit or net export (X-M).考点Relationship between Income ApproanExpenture Approach解析 财政平衡方程为:(G-T)=(S-I)-(X-M)，政府赤字(G-T)的增加的同时，私人储蓄增加超过私人投资(S-I)，或者贸易赤字或净出口(X-M)减少，所以AC不入选，B入选。 G-T越大是政府赤字越大，意思是G政府购买越多，T收回的税很少？所以赤字？这样理解对吗

NO.PZ2016010801000053 increase in net export. a increase in tra ficit B is correct. The fiscbalanequation is given as: (G-T)=(S-I)-(X-M), increase in government ficit (G-T) is a combination of increase in private saving over private investing (S-I) ana crease of tra ficit or net export (X-M). 考点Relationship between Income ApproanExpenture Approa解析 财政平衡方程为:(G-T)=(S-I)-(X-M)，政府赤字(G-T)的增加的同时，私人储蓄增加超过私人投资(S-I)，或者贸易赤字或净出口(X-M)减少，所以AC不入选，B入选。net expoet是X-Mtrang ficit是-（X-M）吗

NO.PZ2016010801000053 tra ficit 是啥啊