Question

It is sad, the way she has _____________ a ' once a lifetime ' opportunity

Answer 1

it's sad ,the way she has squandered a 'once a lifetime' opportunity

Answer 2

​It is sad, the way she has ​squandered​ a once in a lifetime opportunity.

In the above sentence it has been tried to convey that someone has missed or wasted a golden opportunity which might come to someone once in a lifetime.

So, the word ‘squandered’ which means ‘wasted’ is apt for sentence.