A.宽度小于基牙颊舌径的1/2,厚度为0.3~0.5mm B.宽度等于基牙颊舌径的1/2,厚度为0.5~0.8mm C.宽度等于基牙颊舌径的2/3,厚度为0.8~1.0mm D.宽度小于基牙颊舌径的2/3,厚度为0.8~1.0mm E.宽度大于基牙颊舌径的2/3,厚度为0.8~1.0mm