Look, the family are _____ their dinner at home. [ ]

A.enjoys to have

B.enjoying having

C.enjoying to have

D.enjoys having

Co(NH₃)₅BrSO₄可形成两种钴的配合物，已知两种配合物的分子式分别为[Co(NH₃)₅Br] SO₄和[Co (SO₄) (NH₃)₅] Br，在第一种配合物的溶液中加BaCl₂溶液时，产生            现象；如果在第二种配合物的溶液中加入BaCl₂溶液时，产生            现象，若加入 AgNO₃溶液时，产生                现象。