谢谢！我已经同时咨询廖现在单位和未来的大学。信息如下，供未来者参考：
1。 现单位可以以DOS letter办理。
2。 未来单位要求等到CIS 的批准通知。Here are what I got from my university: In the past it was sometimes possible to proceed with just the recommendation but we now consistently see requests for evidence that allow only a month to reply with the approval before denying the case... That month may or may not be sufficient time for CIS to issue the approval notice.
新问题是：大家通常需要几周才能等到CIS 的批准通知。做过的前辈们请告知。
