A rough day for cycling

One day Mark and Steve decided to go cycling. Steve told Mark to put on his helmet but Mark boasted, ''I don't need a helmet. I can ride a bike properly without falling. You'll see."

"OK, I guess," said Steve.

The two of them got on their bike, but before they started to ride, Mark suggested, "Why don't we have a race to see who is the fastest biker?"

"OK," said Steve.

The two rode off. Mark was winning but, suddenly, a cat came out of nowhere and a dog ran right after her. Mark took a deep brake and CRASH!!! Steve got off his bike and phoned his mum.

The next thing Steve knew, he was surrounded by his family. His dad said in a deep voice, "That's what happens when you don't wear a helmet."