After going to votes how is the 'No best answer can be selected' .How many votes is necessary?

Zero votes are necessary. The open voting period lasts 2 days, if no answer has the most votes after this time, then no best answer is declared. So if there are no votes or a tie 2 days after the open voting period starts no best answer is selected.

From Mahalo Answers' Help Page: How are best answers selected? The asker has three days from the time the question is asked to select a best answer by clicking the Select as Best Answer button next to the answer they choose. If the asker doesn't select a best answer within three days, the question moves to the undecided questions tab and the community votes for the best answer.At the end of the voting period, which lasts two days, the answer with the most votes is declared the best answer and receives the tip if a tip was offered.

If there's a tie or no best answer has the most votes, the question is closed without a best answer and if a tip was offered the the tip is credited to the asker's account.

There's a button at the bottom of any question that needs voting on that says "Vote for no answer", I would imagine it's picked/needs the same amount of votes as a normal answer does.

I believe just one vote is necessary, or one vote more than any other person who answered the same question got. I have searched but cannot find any proof to the contrary but you may want to ask at contact@mahalo.com.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.