She's a bit heavy going.

她有点难缠。

I found the course rather heavy going.

我觉得这门课相当难。

I find the work heavy going.

我觉得这工作很难。

I found such books too heavy going.

我觉得这样的书太难读下去。

He soon began to find it heavy going.

他不久就发现进行很吃力了。