i'm expecting a pet dog for long but mum has no time to buy [ ] for me

问题描述:

i'm expecting a pet dog for long but mum has no time to buy [ ] for me
a it b one.

b
one是不定代词,可以代替人、事物、物品等,翻译为“一个人(事情、物品等)”;而it这个代词,是确指,就是代替前面提到过的那个名词的,那就成了要买的是前面的那一条狗了,应该是买宠物狗这个类别中不确定的一个,故错误.