NO.PZ2016010802000193
问题如下：
Which of the following most likely contributes to a current account deficit?
选项：
A.High taxes.
B.Low private savings.
C.Low private investment.
解释：
B is correct.
A current account deficit tends to result from low private saving, high private investment, a government deficit, or a combination of the three. Of the choices, only low private savings contributes toward a current account deficit.
考点：Trade 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 deficit ）所以B选项正确。
本体如何通过题目判断该用那个公式呢？
