Those boys _____ many times not to go on line, but it doesn’t make any difference.

A．have told

B．told

C．have been told

D．were being told

（）是指事前（损失发生以前）对风险承担的价格补偿。

A.风险分散

B.风险对冲

C.风险转移

D.风险补偿