B. Kálmán: The periodicity of sunspots: what is wrong with it? A. Patkós: The mass of quarks P. Hraskó: The paradox of twins G. Márk, P. Vancsó, L. P. Biró: Perfect devices of nanoelectronics from faulty graphenes? OPINIONS G. Bencze: The "ranging" of eminent scientists' merits TEACHING PHYSICS M. Jendrék: How to teach physics in an easy and interesting way M. Hömöstrei: International Young Physicists' Tournament EVENTS