Mr Healy reasoned that the main constraints on an animal's CFF are its size and its metabolic rate.

Healy先生推断，动物CFF的主要限制来自于其体型及其新陈代谢速度。

For example, one main constraint on how many podcasts we make each week is the amount of time we have each day.

例如，我们每周制作多少播客的一个主要限制是我们每天的时间。