film-mulching of double line width ridge
width ridge and furrow irrigation
optimum width of ridge and furrow
ridge-ridge transform fault
diagonal ridge for hip roof，vertical ridge for gable roof
upper ridge (upper-level ridge)
pulse width modulate digital pulse width modulation tech-nique
45cm ridge after narrow row solid-seeding
Abnormality of the ridge line
agro-foresty and contour ridge tillage technique
ahead of High-altitude ridge