29:45
1
student
03:16
0
07:57
0
21:25
0
10:59
6
05:01
1
11:12
6
11:22
2
11:05
4
26:18
14
24:23
3
06:23
6
07:00
5
17:05
5
11:12
33
09:41
38
15:29
21
12:36
9
12:51
4
08:31
8