A dog chases a sheep in an enclosure .
It is likely that a dog is chasing a sheep that has his bone in it 's mouth , in an enclosure .
It is impossible that a dog is chasing a sheep that has his bone in it 's mouth , in an enclosure .
It is likely that a dog is chasing a sheep that has his bone in it 's mouth , in an enclosure .
A dog is chasing a sheep that has his bone in it 's mouth , in an enclosure .