在下列四组数中,不是勾股数的一组是( )
A:15,8,17
B:9,12,15
C:3,5,7
D:7,24,25
The company won the bid for the project by saying that it would do the cleaning up afterwards ________.
某件商品9折降价销售后每件商品售价为a元,则该商品每件原价( )