Big and heavy army to protect them
Answer:
Snap it on Brainlesscamera you might find the answer I haven't read these before
Answer: Aqueducts
Explanation: They were first developed around 312 B.C., these engineering marvels used gravity to transport water along with the stone, lead and concrete pipelines and into city centers. Aqueducts liberated Roman cities from reliance on nearby water supplies and proved priceless in promoting public health and sanitation.
Cosmologists :)
Oceanographers study the ocean, meteorologists study the weather and geologists study rocks.
Answer:
round 100 CE, reaching its peak around 350 CE.
Explanation: