The Pax Romana was: A:200 years of stability.
B: an experiment in democracy.
C: a giant stadium, in which gladiators fought battles.
D: a deadly plague that killed more than 30% of the population of the Roman Empire.

switch around #3 and #4

explanation:

i hope this , im not 100% on this i really hoped this

sumerians were responsible.

a)scientists

explanation:

the national defense education act had two main goals. the first one was to provide personal that was oriented to defense, including scholars, engineering students and so on. the other goal was to provide financial assistance for the students who would be enrolling at colleges and universities in the 1960s.

the national congress's powers over the states were specific and definite: it had the sole power to negotiate treaties, declare war, and make peace. all powers not granted to congress were reserved for state governments. congress had no power to levy taxes, for example.