All those second-hand goods are sold at before．
A. 30％as lower price as
B. 30％as low a price as
C. as 30％low price as
D. 30％lower price than
网友回答
A. 30％as lower price as
(答案→)B. 30％as low a price as
C. as 30％low price as
D. 30％lower price than
解析：考查倍数被动法。本句中的30％也是倍数的一种表达。倍数表达有三种：1. “A+倍数+形容词或副词的比较级+than+B”， 2.“A+倍数+as+形容词或副词的原级+as+B”， 3. “A+倍数+the size/height/length/width， etc+of+B”， 4. “……times+what+从句”。句意：所有这些二手车都是以以前的价格的百分之30出售。