回複：need help for I-485: how to fill list of memberships

Dear teachers and friends:

I wonder in I-485 if I must fill the membership/organizations I attend.

I was student memberships of ASCB (american society of cell biology) and GSA (genetics society of america). However, I forgot the exact starting and ending date. What should I fill in these blanks? Also, what should I fill for the "location and nature" ? - Ask Google

Thank you very much for the help!