nuts and bolts

If we look at the nuts and bolts of the plan, what problems are there?

如果我们探讨一下这份计划点，会发现什么问题？

She has invented a nifty little gadget for undoing stubborn nuts and bolts.

她发明了一种灵巧小工具用来松开紧固螺母和螺栓。

He worked there for two years, long enough to learn the nuts and bolts of the business.

他工作了两年，已经学会了个行业知识。