US Immigration from China

How is everybody here go about providing this one below:

"Affidavits sworn to or affirmed by at least two people who have known both of you since your conditional residence
was granted and have personal knowledge of your marriage and relationship."

(Thanks in advance)!

Hello All,

We are starting our I-751, Petition to Remove Conditions on Residence right now, and I have a question about WORK AUTHORIZATION. The WORK AUTHORIZATION for my spouse has expired and we forgot to renew it.

Does anyone know HOW WE CAN RENEW OUR WORK AUTHORIZATION WHILE WE ARE DOING OUR I-751?

Hello All,

We are starting our I-751, Petition to Remove Conditions on Residence right now, and I have a question about Part 5 (Information about your children).

Does anyone know if this is where I complete the information about the child that we have together after marriage?

Hello All,

We are starting our I-751, Petition to Remove Conditions on Residence right now, and I have a question about the service center and the service center address. Does anyone know where I can find the service center and the service center address?

Hello All,

We are starting our I-751, Petition to Remove Conditions on Residence right now, and I have a question about the fee. I used the online calculator and it said the total amount will be $680.00

Does anyone know if the amount is correct?