If that price is too low,he says, it will not adequately cover the expense of fuel,fertilizer, herbicides and equipment.

VOA: standard.2010.07.29

And b, they have what's called a low expense ratio since they're easy to implement, you don't pay anyone to be brilliant to implement if for you.

但是他们的费用比率很低,因为这种做法很容易，你不需要,有多聪明就能去实施。

麻省理工公开课 - 计算机科学及编程导论课程节选