He never made a will, to the best of my knowledge.

据我所知，他从未立过遗嘱。

To the best of my knowledge, you can't.

以最好的据我所知，你不能。

To the best of my knowledge, none have been successful.

据我所知，没有一次是成功的。

To the best of my knowledge, you were asking me about …

据我理解，你刚才问我的问题是关于……。

The text is free of factual errors, to the best of my knowledge.

就我所知，这篇课文中没有事实性错误。