A derrick will show how pulleys lift heavy weights, and a sluice gate will show how using levers to turn rack and pinion gears can lift the heavy metal gates and allow the water's flow to power the machines.
(A derrick; will show; how pulleys lift heavy weights) Context(A derrick will show,List([0, 19))):(pulleys; lift; heavy weights) (a sluice gate; will show; how using levers to turn rack and pinion gears can lift the heavy metal gates and allow the water's flow to power the machines) (gears; allow; the water's flow to power the machines) Context(gears allow,List([121, 167))):(the water's flow; to power; the machines)
A derrick will show,List([0, 19)) gears allow,List([121, 167))
A derrick pulleys a sluice gate gears the water's flow
will show lift will show allow to power
how pulleys lift heavy weights
heavy weights
how using levers to turn rack and pinion gears can lift the heavy metal gates and allow the water's flow to power the machines
the water's flow to power the machines
the machines