A.8% B.9% C.10% D.12%
A.20mm B.15mm C.10mm D.5mm
A.最高點(diǎn)之間的高差 B.2點(diǎn)之間高差的平均值 C.3點(diǎn)之間高差的平均值 D.4點(diǎn)之間高差的平均值