The girl ________at the party yesterday is missing today.

A．referring to

B．refer to

C．referred to

D．to refer to

下列离子在溶液中能大量共存的是（   ）。

A．Na⁺、CO₃^2-、SO₄^2-、H⁺

B．K⁺、AlO₂^-、H⁺、Cl^-

C．Fe²⁺、K⁺、H⁺、NO₃^-

D．Al³⁺、H⁺、NO₃^-、SO₄^2-