A.PCl3 B.PCl5 C.AsCl3 D.SbCl3
A.NCl3 B.PCl3 C.AsCl3 D.BiCl3
A.K3PO4和K3P B.KH2PO4和PH3 C.KH2PO3和K3P D.KH2PO2和PH3