15.有两根长分别是20厘米和30厘米的木棒,若不改变木棒的长度,要钉成一个三角形框架,则应在下列木棒中选取( )厘米的木棒.
0 297485 297493 297499 297503 297509 297511 297515 297521 297523 297529 297535 297539 297541 297545 297551 297553 297559 297563 297565 297569 297571 297575 297577 297579 297580 297581 297583 297584 297585 297587 297589 297593 297595 297599 297601 297605 297611 297613 297619 297623 297625 297629 297635 297641 297643 297649 297653 297655 297661 297665 297671 297679 366461
| A. | 10 | B. | 20 | C. | 50 | D. | 60 |