<image>(2010 Shangrao County Simulation) The diagram shows the travel curves of cars A and B. Please observe carefully and answer the questions.
(1) Are the distances traveled by the two cars proportional to the time? If so, what is the ratio?
(2) Observing the graph, which car has a higher speed?
(3) What is the average distance traveled per hour by cars A and B respectively?
(4) When car A reaches point B, how many kilometers is car B from point B?