The students should ________ to choose their own clothes. It will be a good way _____ themselves happy.

A．allow, to keep

B．allowed, keeping

C．be allow, keeping

D．be allowed, to keep

由药品生产、经营企业按国家规定制定的价格称为（）

A.药品零售价

B.药品市场调节价

C.药品国家价

D.药品政府定价、政府指导价

E.企业零售价