oil shale and oil shale residue
utilization of high and low grade heat energy
Adjustable high-and-low stroke
analysis of low and high runoff
Axes of high and low temperature
circulation of high and low temperature
design high and low water level
exploitable sulfur-containing and high grade bauxi
function of high and low by-pass system
Gathering with high and low pressures
harbour of big high and low water level difference
high and low altitude jet stream
high and low angles of fire
high and low contrast acuity
high and low corrugated structure
high and low dam combination
High and Low Electric Distribution