The following question is currently in the hotlist: https://math.stackexchange.com/questions/1196661/is-there-any-complete-logical-connective.
I think this is a bad question. Firstly, the title does not match at all the content of the question. Secondly, the OP does not show any attempt to work out the solution. Finally, questions about complete sets of connective were asked on the main site before and were answered. While this question is not an exact duplicate of the previously asked questions, it is in the same spirit and reading the previous questions would give the OP the proof techniques he needs to answer his own question.
Despite this, the questions received upvotes and has an answer. I don't really understand why this question is judged good by the community, while some questions of similar quality are immediately closed as missing context. Shouldn't this question be closed? Or is it too late, just because it already has an answer?