在下列强酸性溶液中，能大量共存的是

A．Ca²⁺、K⁺、HCO₃^—、OH^—

B．Na⁺、ClO^—、H⁺、MnO₄^—

C．Fe³⁺、Mg²⁺、Cl^—、SCN^—

D．K⁺、NH₄⁺、SO₄^2—、Cl^—

More and more people in Shanghai choose to go to work__________ underground.

A．in

B．with

C．by

D．for