នេះ Presentation មិន​មាន​ក្នុង​ភាសា​របស់​អ្នក, មើល​ក្នុង: English (en),
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Presented By: Roland Bunch

Event: ECHO East Africa Highlands Symposium 2014 (27 តុលា 2014)

A-frame levels can be used to trace contour lines for soil conservation, or irrigation ditches at ½ % slope. They are highly accurate, and cost nothing.