What building material did the romans make using cement, sand, gravel, and water? concrete asphalt adobe brick

Brick or stone, first they grinded it into a mortor and poured it into troughs or open slabs and then let it harden by the sun or in a big fire pit

In the late fifteenth century, a major world power that established colonies in the era of old imperialism was france or germany or spain. their colonial activity was mainly limited to america or africa or asia.