As some experts say, shopping by television will never take ________ place of shopping in stores,

because many people find shopping at a store is ________ great enjoyment.[ ]

A. /; a  

B. the; a

C. a; the  

D. a; /

北京沙尘暴近年来得到明显改善，对其贡献最大的因素是（）

A.环保人士

B.香山红叶

C.汽车限行

D.三北防护林