for safe, the answer is from 张哲瑞联合律师事务所web

I-485 常见问题及解答:

2. I-485申请中哪些文件需要原始件？
只有体检报告和你的照片要原始件。

所有跟帖： 

• My employment verification letter is also original -usedtobeadoctor- ♀ (0 bytes) () 06/30/2007 postreply 14:48:06

• needless to say your signature pages of forms -gc2020- ♂ (0 bytes) () 06/30/2007 postreply 14:55:04