单项选择题
A.D=Th+Lh B.D=Th-Lh C.D=2Th+Lh D.D=2Th-Lh
A.K1+375.25 B.K1+149.5 C.K1+450.5 D.K1+224.25
A.D+λ B.D-λ C.Dλ D.D/λ