hierarchy
hi-fi
HI-GAS
high
high-absorbency
high-absorbing
high-acceleration
high-activity
high-alkali
high-alloy
  high-altitude
high-alumina
high-and-low
high-angle
high-antiknock
high-apogee
high-ash
high-attenuation
high-back
high-bake
high-bandgap