1·Building such a bridge over the bay was a hard nut to crack but the local government made it within two years.
在海湾上建造这样一座桥是一件困难的事情，但当地政府在两年内完成了。
2·Sometimes, it is a hard nut to crack without an expert's help.
有时候，如果没有专家的帮助，这是一件很难解决的事情。
3·The problem of hunger worldwide is a hard nut to crack. I'm afraid that scientists need to put in more efforts.
全球性的饥饿问题是个棘手的问题，恐怕科学家们需要付出更多的努力。
4·Each has his own hard nut to crack.; Each has his own trouble.
各有一本难念的经。
—— 《新英汉大辞典》
5·A hard nut to crack and find!
一种难以寻找而且难以对付的坚果。
6·Sudan was a hard nut to crack.
苏丹真的是难啃的骨头。
7·I know he, he is a hard nut.
我认识他，他是个感恩不化的人。
8·I know! He's a hard nut to crack.
我知道。他是个难以了解的人。
9·Mr. White is a hard nut to crack.
怀特先生是个难以对付的人。
10·He's a hard nut to crack.
他是一个难对付的家伙。