5.满足-$\sqrt{3}$<x<$\sqrt{5}$的整数x的个数是( )
| A. | 1 | B. | 2 | C. | 3 | D. | 4 |
20.观察点阵图的规律,第10个图的小黑点的个数应该是( )

| A. | 41 | B. | 40 | C. | 51 | D. | 50 |
19.
如图,在平面直角坐标系上有个点A(-1,0),点A第1次向上跳动一个单位至点A1(-1,1),紧接着第2次向右跳动2个单位至点A2(1,1),第3次向上跳动1个单位,第4次向左跳动3个单位,第5次又向上跳动1个单位,第6次向右跳动4个单位,…,依次规律跳动下去,点A第2015次跳动至点A2015的坐标是( )
0 293393 293401 293407 293411 293417 293419 293423 293429 293431 293437 293443 293447 293449 293453 293459 293461 293467 293471 293473 293477 293479 293483 293485 293487 293488 293489 293491 293492 293493 293495 293497 293501 293503 293507 293509 293513 293519 293521 293527 293531 293533 293537 293543 293549 293551 293557 293561 293563 293569 293573 293579 293587 366461
| A. | (504,1008) | B. | (-504,1007) | C. | (503,1007) | D. | (-503,1008) |