他正好有我需要的零件，那真是走运。

He had exactly the part that I needed, so that was ___a ___stroke ___of ___luck.

仅一次面试就得到这份工作真是走运。

Getting the job after just one interview was ___a ___stroke ___of ___luck.

在二手书店找到那本稀有书籍真是幸运。

Finding that rare book in a second-hand shop was ___a ___stroke ___of ___luck.