This is a tough nut to crack. It's going to take some time to figure out.

这是一件棘手的事。要花些时间才能想出来。

youdao

My new boss is a tough nut to crack. I never know if he's pleased with my work.

我的新老板是个很难相处的人。我永远也不知道他是否对我的工作满意。

youdao

There are some promising drugs in the pipeline. But it's been a really tough nut to crack.

有一些前景不错的药品已经在研发之中，但要真正实现确实还很不容易。

youdao

There are some promising drugs in the pipeline. But it's been a really tough nut to crack.

有一些前景不错的药品已经在研发之中，但要真正实现确实还很不容易。

youdao