一Mary said Mark started the fight and that David simply defended himself.

一 I don’t believe it. Those two hate each other. Anyway, ___________. 

A．It takes two to tango.团结才是力量

B．Two wrongs don’t make a right.两个错加不出一个正确来。

C．Attack is the best means of defense.进攻是最好的防御。

D．You can take a horse to water, but you can’t make it drink.你可以把马牵到水边，但你不能让它喝水。

当消费者购买来自于另一行业的替代产品或者服务的“品牌转换成本”越低，替代品对这个行业未来利润的威胁就越大，行业风险也就越大。( )