—Do you know the boy _____ is sitting next to Peter?

—Yes. He is Peter's friend. They are celebrating his _____ birthday. [ ]

A. who; ninth

B. that; nineth

C. /; nineth

D. which; ninth

下列离子能在pH为13的水溶液中大量共存的是（　　）

A．Ba²⁺、Na⁺、CO₃^2-、Cl^-

B．K⁺、SO₄^2-、Mg²⁺、NO₃^-

C．Fe³⁺、Cl^-、Na⁺、H⁺

D．Cl^-、K⁺、CO₃^2-、Na⁺