Pine shavings.

[wilomn]

my friend had 3 balls use pine shivings all 3 balls died. he used aspen the ball didnt die.

My friend who rides bikes crushed a testicle. My other friend, who rides trikes, didn't. Therefore, and conclusive beyond even the remotest shadow of a whisker of doubt, riding bkes causes cancer and riding trikes prevents it.

One of us is sarcastic, the other simply ignorant.

Which one do you think you are?