It isn't quite _____ that he will be pre

It is the only time in history that two Nobel Prizes ________ to the same person.

A．have been given

B．had been given

C．have given

D．will give

现代电力系统的特点是什么？

药品监督管理部门批准开办药品经营企业，除依据应具备的开办条件规定外，还应遵循的原则是（）

A.公平合理的诚实信用

B.市场需求和社会承受力

C.安全有效和市场需求

D.遵循合理布局和方便群众购药

There are many supermarkets in this town, but we think this is _______ of all.

A．good

B．well

C．better

D．the best

维生素C具有还原性是因分子中存在

A．羟基
B．羰基
C．半缩醛
D．烯二醇
E．伯醇羟基