有这么一道题目：Suppose that a country experiences inflation while the nominal exchange rate and the price level in its trading partner remain unchanged. What will happen to the country's real exchange rate and to net exports? 它的解释我看不太懂：The correct answer is The real exchange rate will rise; net exports will fall. The change in the real exchange rate equals the change in the nominal exchange rate minus the difference between inflation abroad and domestic inflation. In this case, the difference is negative, so the real exchange rate rises and net exports fall. 为什么说the difference is negative的呢？