Are you sure you've got that the right way round?

Make sure that your work surface is at a comfortable level.

And he was very sure that the answer was-Aellianahad not.

"Can you be sure that the hacker's in the same country as the computer?"

"How can you be so sure that the answer's here?"

Make sure that your sources for health information are current and accurate.

People don't mind taxes so much if they're sure that everybody's paying the same.

"But make sure also that we are not still around at four o'clock!"

"Are you sure that none of the servants came in here?"

Make sure that all your equipment operates according to the same 802.11 standard.