单项选择题
A.手工钢锯 B.砂轮切管机 C.手工锉 D.氧—乙炔焰
A.700 B.800 C.1 000 D.1 200
A.1/10~1/5 B.1/15~1/10 C.1/20~1/10 D.1/15~1/5