Now the Chinese eat      as they actually need every day.

A．twice as much protein

B．twice protein as much

C．protein as twice much

D．protein twice as much

对下列未知盐的稀溶液所含离子的检验中，作出的判断一定正确的是 [ ]

A.当加入氯化钡溶液时不产生沉淀，当加入硝酸银溶液时，有不溶于稀硝酸的白色沉淀生成，可判定含有Cl^-

B．加入硝酸钡溶液有白色沉淀生成，再加稀盐酸酸化沉 淀不消失，可判定含有SO₄^2-

C．加入NaOH溶液，有白色沉淀产生，可判定含有Mg²⁺

D．加入盐酸后有无色无味气体逸出，此气体能使澄清石灰水变浑浊，可判定含有CO₃^2-