Task: Question Generation
Input (English): Background Paragraph: When wind waves approach to coast area from deep water, the waves change their heights and lengths. The wave height becomes higher and the wavelength becomes shorter as the wave velocity is slowed when ocean waves approach to the shore. If the water depth is sufficiently shallow, the wave crest become steeper and the trough gets broader and shallower; finally, the ocean waves break at the shore. The motions of wave breaking are different with along to the steepness of shores and waves, and can be categorized by below three types.[11][12]. 
Story: The tourist village had two beaches: Coral beach with nice sand and deeper water was preferred by families, and Surfer beach which  had shallow water was a surfer's heaven.
Output (English): Which beach had waves with a narrow and deep trough?