Is each of these conditions necessary for knowledge?
(I.e., In order for S to know that p, must S believe that p? In order for S to know that p, must p be true? In order for S to know that p, must S be justified in believing that p?)

Are these three conditions jointly sufficient for knowledge?
(I.e., If S believes that p, and p is true, and S is justified in believing p, must S know that p?)