behaviour到底可数吗为什么可以用 bad behaviours呢

问题描述:

behaviour到底可数吗为什么可以用 bad behaviours呢
到底什么时候可以用复数的啊
如I was scolding him for his bad behaviours at school.

不可数的...His friendly behaviour was a cloak for his evil intentions;Everyone condemned his foolish behaviour...