A:must have worked
B:should have worked
C:may have worked
D:should work
下列哪一种行为不属于先天性行为 ( )
1512
1845
3322
2575
2821
1620
25
32
54
45
13
43
下列地形区不是位于北方地区的是( )
儒家学派的创始人是( )