A.ω=30° B.ω=18°-30° C.ω=40° D.ω=15°
A.γ。=20° B.γ。=30° C.γ。=40°
A.三等砝碼 B.四等砝碼 C.五等砝碼 D.1/10000 E.1/20000 F.1/400