First thing we have to do is find out where it's come from.

"The first thing I am going to do is see a doctor and find out the truth."

All these things, and much more, he must find out.

The first thing we have to do is find out.

"The only thing I'm interested in right now is finding out what happened," he said.

"The first thing you should do is find out your credit score," Mark said.

The only thing we can do is find out what we're made of.

"The only thing to do is find out," she muttered to herself.

The first thing we need to do is find out the king's schedule of public appearances.

The things you could find out, if you kept your eyes open!