I think the answer to this is D.
Answer:
They acted like a secret police force.
Explanation:
They acted as a secret police force. The Praetorians were known to engage in espionage, intimidation, arrests and killings to protect the interests of the Roman emperor.
Answer:
france and U.S who laid claim
Steak engine made water power obsolete
Clock? I think. I know they invented the calendar