区分 would have been born 和would be bornwithout China‘s family planning policy,the world’s seven billionth person would have been born six years ago 为什么是would have been born 而不是would be born

区分 would have been born 和would be born
without China‘s family planning policy,the world’s seven billionth person would have been born six years ago 为什么是would have been born 而不是would be born

是对过去的假设.
已经发生过了.用完成时
WOULD BE 是对未来假设
比如你告诉某人什么事.我对你说YOU SHOULD NOT HAVE TOLD HIM.. 对过去假设,因为你已经说过了.