A.真誤差 B.似真誤差 C.偶然誤差 D.平均誤差
A.1′ B.6″ C.5″ D.10″
A.LL⊥VVCC∥HHHH⊥VV B.LL∥VVCC⊥HHHH⊥VV C.LL⊥VVCC⊥HHHH∥VV D.LL⊥VVCC⊥HHHH⊥VV