Arecent theory is that rather than lugging giant blocks of limestone miles over land to form the pyramids, ancient egyptians may have:
a. learned to use telekinesis, possibly from aliens, to float the blocks into place
b. used an advanced system of ramps, pulleys, and levers
c. carved the pyramids from hills already in place, rather than build using blocks
d. invented a form of concrete, allowing them to pour wet concrete into moulds