A:中国近代史的开端
B:给沙俄侵占我国领土提供可乘之机
C:刺激了列强掀起瓜分中国的狂潮
D:使清廷成为洋人统治中国的工具
He turned from side to side, eyeing himself in the mirror with a serious, studied ______ that soon changed into a smile.