The class _____ my daughter studies in _____ fifty-six students.

A．which; consists of

B．where; is made up of

C．which; makes up

D．where; is consisted of

为除去混入CO₂中的SO₂和O₂，下列试剂的使用顺序正确的是：  (　 　)

①饱和Na₂CO₃溶液；②饱和NaHCO₃溶液；③浓H₂SO₄溶液；④灼热的铜网；⑤碱石灰

A．①③④

B．②③④

C．②④③

D．③④⑤