—The Kiwi fruits in this supermarket are sale now, and they are sold the pound.
— Really? How much cheaper are they?
A. for; in
B. on; by
C. for, by
D. on, in
网友回答
A. for; in
(答案→)B. on; by
C. for, by
D. on, in
解析：考查固定搭配。Be on sale正在销售；by the pound 以磅为单位。所以选B.