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

The mongols were descendants of a. pastoral nomadic tribes b. tibetan tribes c. shang nobility

The british used to convince americans to support the allied war effort

All of the following are reasons why people wanted the u.s. government to acquire hawaii except which one? a. it was an ideal location for a ship refueling station or permanent naval base. b. many americans knew it would be an ideal place to vacation. c. it was an ideal location for a lucrative sugar production industry. d. many missionaries hoped to convert the large native population to christianity.