if a requester blocks/prevents us from hits,how can we know and how many blocks leads to suspension of our account.
Usually you will get an email from Amazon telling you that you got a block from a requester and how it can hurt your account. You can also write to Amazon and ask them if you want to be sure, use the contact form on mTurk to do that. I just did and found no blocks yay me! They say 3 hard blocks and you will lose your account, so you might want to make sure you don't have any just to be safe.
Hurray,the requester has unblocked me,on my request I have unblocked you. It's a lot of work to go through all these hits especially when they aren't very good. I appreciate your willingness to ask to be unblocked.