13.图1是一个长和宽分别m,n的长方形纸片,如果它的长和宽分别增加a,b,所得长方形(图2)的面积表示错误的是( )

| A. | (m+a)(n+b) | B. | m(n+b)+a(n+b) | C. | mn+b(m+a)+a(n+b) | D. | mn+bm+an+ab |
5.如果a=(-π)0,b=(-0.2)-1,c=(-$\frac{1}{2}$)-2,那么a、b、c三个数的大小为( )
0 294399 294407 294413 294417 294423 294425 294429 294435 294437 294443 294449 294453 294455 294459 294465 294467 294473 294477 294479 294483 294485 294489 294491 294493 294494 294495 294497 294498 294499 294501 294503 294507 294509 294513 294515 294519 294525 294527 294533 294537 294539 294543 294549 294555 294557 294563 294567 294569 294575 294579 294585 294593 366461
| A. | a>b>c | B. | c>a>b | C. | a>c>b | D. | c>b>a |