Double channel ditch (W-type ditch)

weeper drain；weep drain；drainage ditch；drain ditch

First-grade and third-grade highway

Gum Rosin N GRADE OR WW GRADE

the method of mixing different grade dies el to change diesel grade

agricultural drainage ditch

airlift oxidation ditch

alternating triple oxidation ditch

ameliorated triple oxidation ditch

an integrated oxidation ditch

ancient buried ditch

asymmetric V ditch

berm of ditch

big ditch

Blind Ditch

Blind ditch drainaging

canal ditch

Carrousel 2000 Oxidation Ditch

Carrousel oxidation ditch