You've got to move your mouse to avoid the asteroids (or whatever they are) untill the shooting star appears (it will be near the bottom of the screen. If you miss it you will need to wait until it appears again.
Here is a guide to the questions if you need it:
http://www.dabontv.com/game382cheatsd.html
Also, you can look up the impossible quiz on youtube to see how to do some of the questions.