Parental investment is the key to understanding sex differences in mating strategies.
当我们爱时,我们总是努力变得比现在更好。当我们努力变得更好时,周围的一切也会变得更好。
谈论社区的利益而不了解个人的利益是徒劳的。
The camera is like a weapon; it's dangerous if you don't know how to use it.