A boy wearing a bike helmet , jeans , and a striped shirt and a girl wearing a green shirt and jeans ride bikes with training wheels down a sidewalk .
It is probably the case that the boy is trying to learn how to stabilize riding on a bike
It is probably the case that the boy is trying to learn how to stabilize riding on a bike
We doubt that the boy is trying to learn how to stabilize riding on a bike
The boy is trying to learn how to stabilize riding on a bike