下列离子在溶液中因发生氧化还原反应而不能大量共存的是

A．H⁺、Na⁺、HCO₃^—、Cl^—

B．H⁺、Ag⁺、NO₃^—、Cl^—

C．SO₄^2—、Na⁺、CO₃^2—、H⁺

D．NO₃^—、^—Fe²⁺、H⁺、Cl^—

The speaker believes that a practical solution to the problem of starvation is to remove obstacles to adequate supply of food rather than to increase production of it.

A．True

B．False