多项选择题
Variable appearance，which may include discoid pieces，up to 10 cm in diameter and 1 to 5 cm in thickness，cylingrical pieces，oval to round or plano--convex pieces．Rhubarb may appear in（）
A．圆盘形 B．圆柱形 C．圆凸形 D．卵圆形 E．多角形