I can make no sense at all of these schools of thought; except, perhaps, by supplying a tacit assumption that aggregate output is incapable of change.

我无法理解所有这些思想流派； 除非提供一个默认的假设， 即总产出无法改变。

In the same way the ordinary supply curve for a particular commodity is drawn on some assumption as to the output of industry as a whole and is liable to change if the aggregate output of industry is changed.

以同样的方式，特定商品的普通供给曲线是根据对整个工业产出的某种假设绘制的，并且如果工业总产出发生变化，则该曲线可能会发生变化。