你知道一个有趣的事实吗？猫一天要睡很多个小时。

Do you know an interesting ___fact? Cats sleep many hours a day.

这是一个简单的事实：太阳从东边升起。

It's a simple ___fact: the sun rises in the east.

我知道她确实在撒谎。

I knew for a ___fact that she was lying.