Contour plowing, Pennsylvania, 1938. Contour bunding, Catalonia, 2007. Contour ploughing or contour farming or Contour bunding is the farming practice of plowing and/or planting across a slope following its elevation contour lines.
1 recurring middle ear infections.  Fluid in the ear may be accompanied by signs and symptoms of allergies or an upper respiratory infection including congestion, runny nose, post nasal drip, or watery eyes.
Air-fluid space is what the middle ear represents. This means there is always some amount of fluid there. But when fluid increases in the ear it generally causes pulsing in ear no matter what was the reason of actual increase. It can be infection, or inflammation, or Eustachian tube dysfunction.