By the time he was twelve, Edison ________ to make a living by himself .

A．would begin

B．has begun

C．had begun

D．was begun

下列不属于银行绩效考评指标中风险管理类指标的是（）。

A.信用风险指标

B.市场风险指标

C.流动性风险指标

D.风险调整后收益指标