About National Academy of Engineering's Grand Engineering Challenges for the 21st Century results of 10,000
55:45
08:47
23:52
11:38
02:28
11:37
04:17
24:45
09:10
03:41
04:01
07:17
30:48
01:55
02:32
03:25
04:55
06:05
06:08
11:31
02:54
82:09
03:00
04:45
47:16
06:50
13:01
13:10
04:32
102:36
03:08
14:40
10:26
08:35
12:19
33:43
13:15
02:22
07:47
06:46
06:36
02:30
02:36
04:51
05:13
19:03