关于人教版英语必修一Unit5课文的一个问题

Question

I needed his help because I had very little education. I began school at six . The school where I studied for only two years was three kilomertes away . I had to leave because my family could not continue to pay the school fees and the bus fare . I could not read or write well . After trying hard ,I got a job in a gold mine ,However,this was a time when one had got to have a passbook to live in Johannesburg. Sadly I did not have it because I was not born there , and I worried about whether I would become out of work.
以上是课文选段，我想问的是“Sadly I did not have it because I was not born there , and I worried about whether I would become out of work. ”这句have 的后面为什么跟的是it 而不是one呢？
恳请指教!Orz

Answer 1

因为it是代词，第三人称代指上文的passbook，而one是用来指代前文提到的同类但不是同一个的可数名词（如果是不可数名词用that）。

参考资料：http://baike.baidu.com/view/105801.htm http://zhidao.baidu.com/question/349621621.html

Answer 2

貌似it 和 one 都可以吧