All those second-hand cars are sold atbeforeA. 40％as lower price asB. 40％as low a price as

All those second-hand cars are sold at before
A. 40％as lower price as
B. 40％as low a price as
C. as 40％low price as
D. 40％lower price than

A. 40％as lower price as(答案→)B. 40％as low a price asC. as 40％low price asD. 40％lower price than解析：考查倍数的表达方法。句意：所有的二手车都以原价的40%低价出售。倍数的常用三种表达方法：⑴“倍数+ as + 形容词原级+（ a/an+单数可数名词）+as ”；⑵“倍数+比较级+than ”⑶“倍数+ the + size / length / depth /height +of”，根据结构，可排除ACD，故B为正确答案。

就是这个解释