I've no idea.
I know nothing about that.I don't know.我不知道
I am not clear about this.我不知道,我不清楚.
be ignorant of 不了解,不知道
I am ingnorant of it.我不知道,不了解.
He was not unlearned in history.他对历史并非无知.
be insensible of 不知道
I am insensible of it.我不知道
We are not insensible of your kindness.我们并非不知你的好意.
be unaware of 不知道,不注意
I am unaware of it.我不知道.我没察觉.
be unaware of the danger没有觉察到危险
He was unaware that I was present.他不知道我在场.
in the dark 在黑暗中,秘密地,不知道
I am in the dark.我不知道.
be in the dark about完全不知道,蒙在鼓里
I am in the dark about...我不知道.
be in the dark as to完全不知道,蒙在鼓里
I am in the dark as to...我不知道...
keep sb.in the dark不让某人知道
leave sb.in the dark不让某人知道