It sounded impossible, but it was more than we'd had a moment ago.

"One hundred dollars, though that sounds impossible, is still far too expensive."

And so, though it sounds impossible to rescue Tom, there may.

I know this will sound impossible but it isn't.

I know that may sound impossible, but people do read for fun.

It sounds impossible, but this entire trail was cut on purpose.

This may sound impossible - after all, it's the wealthy who get the tax breaks, not the poor.

I know it sounds impossible, but I'm telling the truth.

I know it sounds impossible, but he's still alive in there.

I know that sounds impossible, but they seem to think they can do it.