How many years did it take the modern engineers to figure out how the roman concrete was made out of?

Which distinctive feature of the notre dame cathedral allowed it to accommodate its large stained glass windows? a. its barrel vaults b. its flying buttresses c. its quadrant arches d. its square bays

Was president roosevelt justified in ordering executive order 9066, which resulted in the internment of japanese american citizens? write a clear claim that responds to this writing prompt.

Which of the following encouraged westward expansion? a. the government decreased the price of federal land. b. each of these represents actions taken to encourage westward expansion. c. the government decreased the price of federal land d. the second national bank lowered the cost of borrowing money (reduced interest rates)