A.30° B.45° C.60 ° D.90°
A.推力;稍有切削 B.壓力;不切削 C.推力;不切削 D.壓力;稍有切削
A.減少;增加;降低 B.消除;降低;調(diào)整 C.消除;增加;調(diào)整