It isn’t an excuse for your failure you didn’t know the rulesA. ThatB. BecauseC. WhyD. Ho

问题补充：

It isn’t an excuse for your failure you didn’t know the rules

A. That

B. Because

C. Why

D. How

答案：

(答案→)A. That

B. Because

C. Why

D. How

解析：考查主语从句用法。本句中的it是形式主语。真正的主语是后面的that you didn’t know the rules.that在句中起引导和连接作用，不能省略，也没有什么含义。句意：你不知道规则这不是你失败的借口。故A正确。