VOA News 조회 수 241 추천 수 0 2015.03.19 03:55:49
Finding hidden cracks in large structures, such as bridges and airplanes, can be the difference between life and death, if the flaw leads to a catastrophic collapse. Scientists at Bristol...
|Time: 02:27||More in News & Politics|
원문출처 : http://www.youtube.com/watch?v=zHPMBZSOHks&feature=youtube_gdata