我的祖父母度过了非常艰难的一生。

My grandparents had a very ___hard life.

过去的几个月对你来说一定非常艰难。

The past few months must've been really ___hard for you.

对我们所有人来说，那是一段非常艰难的时期，但它过去了，我希望永远不会再来。

It was a really ___hard time for all of us, but it passed and, I hope, will never come again.