请问这道题说的是reading19的那个balance of payment知识点吗？
问题如下图：
选项：
A. 
B. 
C. 
解释：
NO.PZ2016010802000193 问题如下 Whiof the following most likely contributes to a current account ficit? A.High taxes. B.Low private savings. C.Low private investment. is correct.A current account ficit ten to result from low private saving, high private investment, a government ficit, or a combination of the three. Of the choices, only low private savings contributes towara current account ficit.考点Tra Balance.解析X-M=(S-I)-(G-T)通过上述公式可以得知，较高的 private investment，较低的 private savings 以及较低的 taxes都会引起X-M的降低（ Crrent account ficit ）所以B正确。 这道题为的是什么原因导致的贸易逆差吗？contributes从这个方面理解？
NO.PZ2016010802000193 问题如下 Whiof the following most likely contributes to a current account ficit? A.High taxes. B.Low private savings. C.Low private investment. is correct.A current account ficit ten to result from low private saving, high private investment, a government ficit, or a combination of the three. Of the choices, only low private savings contributes towara current account ficit.考点Tra Balance.解析X-M=(S-I)-(G-T)通过上述公式可以得知，较高的 private investment，较低的 private savings 以及较低的 taxes都会引起X-M的降低（ Crrent account ficit ）所以B正确。 本体如何通过题目判断该用那个公式呢？
NO.PZ2016010802000193 问题如下 Whiof the following most likely contributes to a current account ficit? A.High taxes. B.Low private savings. C.Low private investment. is correct.A current account ficit ten to result from low private saving, high private investment, a government ficit, or a combination of the three. Of the choices, only low private savings contributes towara current account ficit.考点Tra Balance.解析X-M=(S-I)-(G-T)通过上述公式可以得知，较高的 private investment，较低的 private savings 以及较低的 taxes都会引起X-M的降低（ Crrent account ficit ）所以B正确。 谢谢
NO.PZ2016010802000193 问题如下 Whiof the following most likely contributes to a current account ficit? A.High taxes. B.Low private savings. C.Low private investment. is correct.A current account ficit ten to result from low private saving, high private investment, a government ficit, or a combination of the three. Of the choices, only low private savings contributes towara current account ficit.考点Tra Balance.解析X-M=(S-I)-(G-T)通过上述公式可以得知，较高的 private investment，较低的 private savings 以及较低的 taxes都会引起X-M的降低（ Crrent account ficit ）所以B正确。 X-M=(S-I)-(G-T)
请问老师 G-T和T-G是不是影响不大？总需求课件是前面那个，国际贸易这就是后面那个
