***的《沁园春·雪》中“一代天骄,成吉思汗,只识弯弓射大雕”指的是( )
A:铁木真
B:忽必烈
C:阿保机
D:阿骨打
已知向量a,b,c满足a=b=a·b=2,a-b·b-2c=0,则b-c的最小值为( )
Live or not, a famous American actor, was always expecting ______ an Oscar and finally he made it.