下列分子中心原子是sp2杂化的是 [ ]
A.PBr3
B.CH4
C.BF3
D.H2O
C
Titanic 3D moved all audience to tears once again, ________ our attention to Cameron ‘s films and the definition of true love.
A.turning
B.to turn
C.turned
D.being turned
背景
问题
费率计算中哪些是正确的,哪些欠妥,欠妥的应该如何计算