But when this idea was mentioned to him he said nothing.

But is this reason enough not to mention the central idea of my book?

I told him this sort of act wasn't in my line at all, and he never mentioned the idea again.

It was not the first time she mentioned the idea.

She certainly never mentioned the idea of giving up my seat.

The idea of reform as such is not otherwise mentioned.

He finally explained what it was when I mentioned the idea of going home.

I haven't mentioned the idea to her in case you objected.

The book also mentioned the idea of a "world's fair".

But they found nothing, and no one's ever even mentioned the idea since.