7.下列算式正确的是( )
0 287431 287439 287445 287449 287455 287457 287461 287467 287469 287475 287481 287485 287487 287491 287497 287499 287505 287509 287511 287515 287517 287521 287523 287525 287526 287527 287529 287530 287531 287533 287535 287539 287541 287545 287547 287551 287557 287559 287565 287569 287571 287575 287581 287587 287589 287595 287599 287601 287607 287611 287617 287625 366461
| A. | 2+$\sqrt{2}$=2$\sqrt{2}$ | B. | $\sqrt{{3}^{2}-{2}^{2}}$=$\sqrt{{3}^{2}}$-$\sqrt{{2}^{2}}$=3-2=1 | ||
| C. | $\sqrt{8}$-2$\sqrt{2}$=0 | D. | $\sqrt{(1-\sqrt{3})^{2}}$=1-$\sqrt{3}$ |