Sentence examples for contributed not once from inspiring English sources

The institutional culture and mismanaged expectations of the space shuttle program have contributed, not once but twice, to the destruction of craft and crew.

Not once?

No, not once.

Not once, but twice.

"Not once again.

"Not once," he said.

"Not once?" "Not once".

It was twice, not once.

"Not once has it stopped".

Not once in my life".

"NOT once in a decade.