It's easier to fall into bad habit than into good

问题描述:

It's easier to fall into bad habit than into good
It's easier to fall into bad habits than into good( ).
A.one B.ones C.other D.others.
为什么?>>

本来应该是:It's easier to fall into bad habits than into good(habits).
但由于前面“bad habits”中已经有了“habits”这个单词,因为为了避免重复,用“ones”代替前面所指的“habits”.