NO.PZ2018062003000114
问题如下：
A client has asked you to explain the differences between potential GDP and real GDP:
选项：
A.Growth in potential GDP measures how rapidly the total economy is expanding.
B.If real GDP is below potential GDP, the aggregate price level has downward pressure.
C.If real GDP is below potential GDP, the aggregate price level tends to rise.
解释：
B is correct.
Growth in real GDP measures how rapidly the total economy is expanding. If real GDP is below potential GDP, the aggregate price level has downward pressure. If real GDP is above potential GDP, the aggregate price level has upward pressure.
考点：potential GDP
解析：是真实GDP而非potential GDP 能够准确衡量一国GDP的增长情况，所以A选项不入选。
如果当前真实GDP小于potential GDP ，表明该国当前经济不景气，物价就可能面临下行压力，所以B选项正确，而C选项错误。
potential GDP是长期GDP，而real GDP是短期GDP，后者在前者之下按照讲义上的图来看，shortrun肯定是在longrun以下啊，为什么会有price downward的趋势呢？请老师讲细一点
