He hasn't enough money to buy a car,so he'll just have to do without one.为什么不能用it?
问题描述：
He hasn't enough money to buy a car,so he'll just have to do without one.为什么不能用it?
答
one指同一类,it指同一个.
比如：I lost my pen so I have to buy one.买到的新的和丢了的不是同一个.My father gave me a pen and I lost it.爸爸给我的就是我丢了的那个.