Once an answer for a Yahoo question has been chosen, that closes it?

Yes, although if the asker doesn't choose, then once the question goes to vote there can no longer be any answers. Only open questions can be answered.

You click on your face( which on your case is the gray face) it is going to take you on your internet site.Scroll all the way down to Questions and click on the question you asked. Now scroll all the way down to %. a perfect answer and click on the only you enjoyed perfect..it is going to open a container and assist you type in any difficulty else you prefer to declare including thank you or i attempted that and it worked..then click prepare.

Yes.