Before onlookers in a park , a man in a black shirt and rollerblades slides backward down a railing .
It is probable that a man in a black shirt practices his new rollerblading moves .
It is probable that a man in a black shirt practices his new rollerblading moves .
Chances are slight that a man in a black shirt practices his new rollerblading moves .
A man in a black shirt practices his new rollerblading moves .