by Xinhua writer Guo Yage BEIJING, Dec. 29 (Xinhua) -- Another Christmas has come and gone, replete with families and friends exchanging gifts beside a crackling hearth, sharing stories under a Christmas tree and enjoying traditional holiday meals. Others weren't so fortunate, receiving church handouts, curling up in a subway station to avoid the cold or grieving the loss of beloved ones killed by gun violence. The happiness and sorrow of humankind are not related - such a sad truth has been