一种物品或服务的社会边际效益，随其数量的增加而倾向于增加。
参考答案：错
既是合穴，又是八会穴的是
A．足二里
B．尺泽
C．阳陵泉
D．悬钟
E．曲池
In many European countries, one has to decide much earlier what one's career is going to be, and there
is less freedom in changing one's decision _____ one has chosen a particular path. [ ]
A. once
B. before
C. until
D. as
