00:05
0
student
00:05 
08:38
1
04:23
0
04:13
0
00:01
1
00:04
0
00:32
3
00:01
3
13:33
0
00:03
1
00:02
2
00:05
4
08:13
0
00:41:40
1
00:05
4
03:27
0
00:10
1
05:15
0
00:01
4
04:54
2
05:39
19