four-blade
four-bladed
fourble
four-cup
four-cycle
Fourier
fourline
fourling
four-point
four-section
  four-spot
four-stage
fourstage
four-stroke
four-way
four-wheel
four-wheeled
four-wing
frac
fraction
fractional

    four-spot well pattern

    четырёхточечная сетка размещения скважин