It is wrong of me to intrude upon your private thoughts.

There come moments when the thing shines out upon our thoughts.

He seemed to be musing upon his thoughts and to have forgotten them.

For many years there was one question which had continually obtruded itself upon his thoughts.

He did not look back; he was so intent upon his thoughts.

It was a question that had preyed upon his thoughts more than a few times.

And as it was not for many years that any hope appeared, this prevailed very often upon my thoughts.

"I do not wish to intrude upon your thoughts and schemes."

She was only conscious of Denham as a block upon her thoughts.

I had been too intent upon my own thoughts to notice that until he spoke.