问题
选择题
—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
答案
答案：B
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.