单项选择题

A.划线→锯割→锉削→钻孔;圆锉
B.划线→钻孔→锯割→锉削;半圆锉
C.钻孔→钻孔→锯割→锉削;圆锉
D.划线→锯割→钻孔→锉削;半圆锉