You should say:

　　- what it was

　　- who was with you

　　- why you did it

　　and explain why you think it was unusual or interesting.

　　范文

　　I went to bungee jumping with my best friend recently. The reason is simple. We have our normal daily routine doing the same thing every day, but I want some difference to break the ice and I want adventure. Bungee jumping is the most dangerous activity on the planet. It is a good way of testing your fear limits. Few people would like to try and it is also an unusual extreme sport for me.

　　The hardest part was actually going off the platform. You wanted to do it but the fear kicked in and the fear part of your mind wanted to hold back. However, when I got over it, it was like a free fall rush that stimulates every part of your emotional psyche. Bungee jumping was like a backwards trampoline that made you go really high. You free fell for a long time until the cord caught you. Then, it stretched and bounced you back up, and you free fell again and went back up and back down until the bungee lost most of its energy. It was the best feeling ever. I was buzzing and grinning for a whole day after bungee jumping, but I am not sure whether I have the courage to do it again or not.