The origin of the lever goes back to prehistoric times when people discovered that placing a rock under the end of a strong stick made it easier to lift heavy objects.
(The origin of the lever; goes; back to prehistoric times; T:when people discovered that placing a rock under the end of a strong stick made it easier) (people; discovered; that placing a rock under the end of a strong stick made it easier) Context(people discovered,List([60, 77))):(placing a rock under the end of a strong stick; made; it easier to lift heavy objects)
people discovered,List([60, 77))
The origin of the lever people placing a rock under the end of a strong stick
goes discovered made
back to prehistoric times T:when people discovered that placing a rock under the end of a strong stick made it easier
that placing a rock under the end of a strong stick made it easier
it easier to lift heavy objects