youdao

If one believes in himself, all he needs is just a little bit of luck to fulfill all his dreams.

只要一个人相信自己，他就只需要一点点运气，所有的梦想就都有可能实现。

youdao

I'll take just a cup for luck.

为讨个吉利我就喝一杯。

《新英汉大辞典》

As far as the farmers are concerned, it is just a case of bad luck for the British.

CNN: UK outbreak raises questions

The fact is the financial crisis and the recession were not the result of normal economic cycles or just a run of bad luck.

WHITEHOUSE: President Obama Nominates Director of Consumer Financial Protection Bureau | The White House

Whether it is just bad luck, a misreading of public opinion or being on vacation while a united Republican opposition is hard at work, voters have turned cold to Democratic Presidents and candidates in August.

FORBES: Forget April, August Is Cruel to Democrats