A. Forget to wear and fasten your bike helmet. Now, that's dumb!

Any problem you have, like slipping off a curb or biking too fast down a hill, can end with your head busted on the pavement.

Just a few years ago, few kids or adults wore helmets. Today, even bikers who go to the extreme wear helmets. If you don't, hey, stay home and study.

Here's a tip on how to know if your helmet is positioned properly: walk up to a wall and the front of the helmet should touch the wall before your nose does.

Here is more on bike helmets.