单项选择题
A.50mm B.100mm C.60mm D.80mm
A.1/100~1/300 B.1/1000~1/2000 C.1/1000~1/3000 D.1/100~1/200
A.反铲挖土机 B.抓铲挖土机 C.拉铲挖土机 D.正铲挖土机