He never praises his wife: he just________ her________.     [ ]

A. took; for granted      

B. took; as granted      

C. takes ; for granted      

D. takes ; as granted

平均负荷峰谷差率定义为（）。

A、（（日最大发受电电力-日最小发受电电力）/日最大发受电电力）的均值

B、（（日最大电力-日最小电力）/日最大电力）的均值

C、（（日最大发受电电力-日最小发受电电力）/日最大发受电电力）