20.下列条件中,不能判断四边形ABCD是平行四边形的是( )
0 285460 285468 285474 285478 285484 285486 285490 285496 285498 285504 285510 285514 285516 285520 285526 285528 285534 285538 285540 285544 285546 285550 285552 285554 285555 285556 285558 285559 285560 285562 285564 285568 285570 285574 285576 285580 285586 285588 285594 285598 285600 285604 285610 285616 285618 285624 285628 285630 285636 285640 285646 285654 366461
| A. | AB∥CD,AD∥BC | B. | AB=CD,AD∥BC | C. | AB∥CD,AB=CD | D. | ∠A=∠C,∠B=∠D |