Isn't this a priceless morning, madam ?
真是个千金难买的早晨，夫人。

The mathematics of the theory is too formidable .
理论中的数学太难。

It 's easy to open a shop but hard to keep it open .
创业容易守业难。

Her virtue is like a pathless desert .
她的品德象一片人迹难到的沙漠。

They say that she is a hard nut to crack .
据说她是一个难驯服的女人。

I think you are too hard to please .
我觉得你这个人未免太难满足了。

She considered berenice a little difficult .
她认为白丽莱茜有点难弄。

An athenian never forsook distress .
一个雅典人从来不会见难不救的。

The easy proof of this is left to the reader .
此证明不难，，留给读者。

Fact is inextricably commingled with fiction .
事实与虚构混杂难分。