engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:18
hydrometer is seen immersed in beer at wynwood brewing company on april 25, 2014 in miami, florida. earlier this week florida senate rules committee... - 比重計 個影片檔及 b 捲影像00:11
hydrometer is seen immersed in beer at wynwood brewing company on april 25, 2014 in miami, florida. earlier this week florida senate rules committee... - 比重計 個影片檔及 b 捲影像00:14
dam engineer supervises operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:06
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:08
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:07
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:25
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:22
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:06
at a service station, an automotive technician is seen inspecting the inside of a car's hood. followed by taking a hydrometer reading, u.s.a., 1941. - 比重計 個影片檔及 b 捲影像00:15
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:06
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:16
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:07
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:18
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:21
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:24
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:12
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:08
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:08
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
dam engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:12
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:06
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:15
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:08
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:09
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:14
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:16水力發電
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:14
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:10
ecologist and engineer supervises dam operations using laptop and radio communication for efficiency. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:11
engineers and ecologist collecting water samples for environmental analysis at a hydroelectric dam site. concept of environmental conservation - 比重計 個影片檔及 b 捲影像00:27