我觉得他们的婚姻正在经历一段困难时期。

I think their marriage is going through ___a ___bad ___patch.

经历那段失去工作的困难时期后，他变得更坚强了。

He became stronger after going through ___a ___rough ___patch when he lost his job.

该公司正在努力度过这个由于市场变化而造成的困难时期。

The company is trying to get through ___a ___difficult ___patch caused by market changes.