AC21原文如下：
(j) JOB FLEXIBILITY FOR LONG DELAYED APPLICANTS FOR
ADJUSTMENT OF STATUS TO PERMANENT RESIDENCE- A petition
under subsection (a)(1)(D)for an individual whose application for
adjustment of status pursuant to section 245 has been filed and
remained unadjudicated for 180 days or more shall remain valid with
respect to a new job if the individual changes jobs or employers if
the new job is in the same or a similar occupational classification
as the job for which the petition was filed.
从条文中可见：
1. 对140（petition）的要求是相同或相似工作。
2. 对个人的要求是485 pending 180天或以上。
除此之外对140并没有其它要求。没有规定说140必须是当时跟485关联的那
一份。只要个人有符合要求的485，那么所有相似工作的140都有效。
换句话说，降级后180天跳槽，只要工作相似，即可relink升级回到EB2。
