]后读[iz] 口诀：清清浊浊元浊 Cups, cats, cakes, roofs, flags, keys, faces 以s, x, ch, sh结尾 加-es 在[s][z][?][t?]后读[iz] Classes, boxes, watches, brushes 以辅音+y结尾 变y为i,加es 读[z] Cities, count...