For thousands of years, where there has been a lack of stone, wood or other materials, people learned to make sturdy building blocks from the earth itself.
(people; learned; to make sturdy building blocks from the earth) Context(people learned,List([87, 101))):(people; learned to make; sturdy building blocks; from the earth)
people learned,List([87, 101))
people people
learned learned to make
to make sturdy building blocks from the earth
sturdy building blocks from the earth