He bought some books in the bookstore and his father________ him a lot of money.

A．gives

B．will give

C．ought to give

D．must have done

化学实验中，常将溶液或试剂酸化，下列酸化处理的措施中正确的是

A．定性检验SO₃^2－，将BaCl₂溶液用HNO₃酸化

B．为了提高KMnO₄溶液的氧化能力，用盐酸将其酸化

C．检验某溶液中是否含Cl^— ，用HNO₃酸化的AgNO₃溶液

D．配制FeCl₂溶液时通常加少量HNO₃酸化，减小其水解程度