单项选择题
A.G85 X50.0Y50.0 Z-10.0 R0 F50 B.G81 X50.0Y50.0 Z-10.0 R0 F50 C.G81 X50.0Y50.0 Z-10.0 R5.0F50 D.G83 X50.0Y50.0 Z-10.0 R5.0F50
A.#30 B.#140 C.#2000 D.#5201
A.G17 G90 G02X-30.0Y0 R50.0 F50 B.G17 G90 G03X-300.0Y0 R-50.0 F50 C.G17 G90 G03X-30.0Y0 R-50.0 F50 D.G17 G91 G02X30.0Y0 R50.0 F50