this 问题 has been asked like a bajillion times, but i'll still answer it anyways, 你 can get 奖章 由 contributing to the club u want to earn a medal in. 你 have to 上传 pics, videos, write alot on the club's wall, get involved with the forums, make pop 测试 questions, answer peoples questions...then at a 随意 time 你 get a medalXD hope that helps!
