向存在大量Na⁺、Cl^-的溶液中通入足量的NH₃后，该溶液中还可能大量存在的离子组是[ ]

A．K⁺、Br^-、CO₃^2-

B．Ag⁺、Cu²⁺、NO₃^-

C．NH₄⁺、Fe³⁺、SO₄^2-

D．Al³⁺、H⁺、MnO₄^-

---Waiter! How soon can I get my food? I just have half an hour left before my train leaves.

--- It ______ be ready in five minutes.

A. may                      B. should             C. could                      D need