be ignorant of 一无所知；不知道；不了解

【例句】
That doesn't mean the market has any right to be ignorant of events that are barreling down the pike toward it.
那并不意味着市场有权对纷至沓来的重大事件一无所知。

She appears to be ignorant of this fact.
她似乎不知道这件事实。