Every once in a while you stumble upon extraordinary people that make you really re-think about the current affairs and the ways of the traditional education systems.
You got a .rar file and you don't how to open it, some one asked you to send him "a rar file" or you just need a good archiving software? Download and install WinRAR.
If you can't copy files that are bigger than 2 or 4 GB, usually HD movies and such, on to your USB key, it's usually due to the file system the USB key is formatted to.
The newest findings suggest that a cosmic impact of an asteroid or comet, indeed was the reason why the once mighty dinosaurs don't roam the planet Earth anymore.