Her father had passed away a long time ago.

她父亲已经去世很长时间了。

Someone else told you that I had passed away.

别人告诉你，我去世了。

We just learned that her father had passed away.

我们刚知道她父亲不久前去世了。(说明去世在先，得知在后)。

The next day, she received news that he had passed away.

第二天早上，老夫人得知她丈夫昨晚已逝世的信息。

The world had passed away from him, as his strength ebbed.

这个世界正在从他这里消失，因为他的精力渐趋耗尽。