9.下列各式中,是完全平方式的是( )
0 282595 282603 282609 282613 282619 282621 282625 282631 282633 282639 282645 282649 282651 282655 282661 282663 282669 282673 282675 282679 282681 282685 282687 282689 282690 282691 282693 282694 282695 282697 282699 282703 282705 282709 282711 282715 282721 282723 282729 282733 282735 282739 282745 282751 282753 282759 282763 282765 282771 282775 282781 282789 366461
| A. | m2-m+1 | B. | x2-18x+9 | C. | a2+2ab-b2 | D. | t2-t+$\frac{1}{4}$ |