由实验室自己配置的商品，其中有关物质的量由参考方法定值的标准品为（）.

A.控制物

B.参考物

C.一级标准品

D.二级标准品

E.原级参考物

　　 the great teacher Zhang Lili was in hospital, many people hoped she would get better soon.

A．If

B．Until

C．Before

D．After