A boy in blue shorts and a t-shirt is poised to hit a tennis ball with a racket.
A boy wearing green shorts and a green t-shirt runs on a track.
One boy has blue shorts the other has green shorts.
A boy is either playing tennis or runs on a track.
the boy most likely will not be wearing blue shorts and green shorts at the same time. it is not normal for someone to hit a tennis ball and run on the track at the same time.