我知道她听到这个消息会非常高兴。

I ___know that she'll be really pleased to hear the news.

我不知道是否应该告诉她。

I don't ___know whether I should tell her or not.

我找不到信息，但我知道课是在星期二。

I can't find the information, but I ___know the class is on Tuesday.