p1
33
84
17
90
9
28
64
34
20
31
78
82
27
p2
69
66
1
p3
56
89
10
左闭合B+Tree: 1 <= X < 28 ->p1 28 <= X <66 -> p2 66 < X ->P3
8
55
61
75
36
13
23
92
