all living things depend, directly or indirectly, on green plants for food and oxygen. this film clarifies the difference between food and raw... - 形成層 個影片檔及 b 捲影像00:36
trees and their importance - part 8 of 22. the theme of this film is conservation, with emphasis on the importance of trees as a renewable resource, and their role in water and soil conservation. a number of animated sequences showing the life processes o - 形成層 個影片檔及 b 捲影像00:31
trees and their importance - part 7 of 22. the theme of this film is conservation, with emphasis on the importance of trees as a renewable resource, and their role in water and soil conservation. a number of animated sequences showing the life processes o - 形成層 個影片檔及 b 捲影像00:32
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:16
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:19
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:07
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:34
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:14
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:14
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:36
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:11
microscopic cross sectional view through woody stems to show vascular bundles, xylem, cambium, phloem - 形成層 個影片檔及 b 捲影像00:32