Premise: A child is performing a skateboard trick while another child with a skateboard leans on a wall.

Hypothesis: An older brother teaches his younger brother a new skateboard trick.
it is not possible to tell

Premise: A truck has just crashed into the back of another truck.

Hypothesis: Two truckers crash on a busy freeway.
it is not possible to tell

Premise: Two golden retreiver dogs are running on the grass.

Hypothesis: a young boy runs
yes

Premise: Two tan dogs smell each others faces.

Hypothesis: Two black dogs fight.
no