who引导的主语从句问题____ knows the truth will tell you about it.A.Who that B.WhoeverC.Those who D.Whom that参考答案选：B,这个选项无争议.但A为什么不行呢?
问题描述：
who引导的主语从句问题
____ knows the truth will tell you about it.
A.Who that B.Whoever
C.Those who D.Whom that
参考答案选：B,这个选项无争议.但A为什么不行呢?
答
主语从句只能用who或that引导，而who不能作为先行词
答
如果是选A那么That就要放到who前面引导整个句子,明白了吗?
答
判断定于从句,可以做简法.
A不行,简化后相当于是who will tell you about it.这句话应该是陈述语气.
这题C应该可以,简化后相当于Those will tell you about it.
Those who knows the truth那些知情的人.
有句谚语叫做God helps those who helps themselves.
之所以不选C,应该是和上下文的意思有关.