The price of this washing machine has been increased ________ 15％．

The price of this washing machine has been increased ________ 15％．

A.up

B.to

C.by

D.from

答案及解析： C

解析：

increase后面可能搭配介词to或by。increase to表示“增加到”，to后为结果；

increase by表示“增加了”，by后为幅度。