What did the Maya take to make the rain forests livable?

Round arches allowed the romans to create structures with

Which of these innovations led to increased production in american factories in the early 1800s? a. the use of interchangeable parts b. the construction of canals c. the invention of the mechanical reaper d. the availability of electricity

Plz ive been stuck on this question forever. in 1753 george washington was sent on a mission to a. build a fort at the point where the allegheny and monongahela rivers form the ohio river. b. attack the french at fort duquesne. c. attack the french at fort neccessity. d. deliver a message to the french demanding that they leave the ohio river.