Da Chen tells a good story. Sloped back on a chair at the 23rd Ave. Bookstore, he keeps the small audience at his reading riveted as he describes collecting fertilizer for his family�s garden. "Water buffalo are like humans. The first thing they want to do when they wake up is go to the bathroom. So we were ready, following them with a bucket," Chen says, moving his arms back and forth as if holding a bucket under the rear of a moving water buffalo.