Those who believe the old bromides about the French and their slack work ethic would do well to observe the frenzy of study that seizes this country’s teenagers each June, The New York Times reports. By the hundreds of thousands, they pack themselves into libraries, flood their bloodstreams with stimulants and spend weeks generally cramming for the baccalauréat, better known simply as the “bac,” the exhaustive finishing exam that has racked the nerves of France’s students since the time of Napoleon…