A.液面接觸處彎月面下緣 B.水平觀察與液面接觸處的彎月面下緣最低點(diǎn)處 C.彎月面上緣 D.水平觀察彎月面上緣
A.2mg B.lmg C.5mg D.0.Img
A.0.3% B.0.05% C.0.2% D.0.10%