But two explosions of deadly rioting barely over a year apart are an embarrassing public challenge to the rule of a government that has brooked little dissent since taking power in 1949.

• 保守派人士在近几年来处于掌权地位，主持加紧在宗教和语言方面的控制而且对在2008年京奥林匹克运动会之前爆发的西藏暴力事件给予了一个严厉的回应。