不一样的 before applying 在找工作前, be required 先发生
上次那个 having seen her 见过她之后,之前见过她 didn't know 后发生
not having seen her 之前没见过她 didn't know 后发生
如果是After applying for the job, 就和having applied一样了
having done 基本=after doing
比如having worked here for 10 years, he is experienced.
= after working here for 10 years