"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on Venus and returning him safely to--" [an aide frantically whispers in the president's ear for a moment] "... of landing a man on Venus."
"If you encounter a hex bolt, but you only brought screwdrivers, you can try sandwiching the head of the bolt between two parallel screwdriver shafts, squeezing the screwdrivers together with a hand at either end, then twisting. It doesn't work and it's a great way to hurt yourself, but you can try it!"