Test Chamber 03 - Trying Out Portals

The computer asks you to proceed to the chamber lock, with the entirely unhelpful warning to "mind the gap". Before falling into the gap, put a blue portal on the wall somewhere and go through it to emerge beyond that gap.

Then you'll notice that there's another gap between you and the elevator to the next level. Just create a blue portal on a wall beyond this second gap, then go through the orange portal again and you'll be able to reach the elevator. For whatever reason, the computer mentions Bring Your Daughter to Work Day to encourage you to have her tested. Weird. Who knows if your character even has a daughter. Or is someone's daughter. But I digress.