once-in-a-lifetime

剑桥词典

A once-in-a-lifetime experience or opportunity is very special because you will probably only have it once .
一生中难得一次的；千载难逢的；难能可贵的
A tour of Australia is a once-in-a-lifetime experience . 澳大利亚之行是一生难得的一次经历。 返回 once-in-a-lifetime