Having to meet unlimited wants and needs with limited resources is called
a. cost
b. scarcity
c. a shortage
d. an opportunity cost

What events caused the united states to intervene in southwest asia?

The creation of the trans-siberian railway allowed people to travel across russia. how could this railway impact russian culture?

Ascientist is explaining how background cosmic radiation gives evidence of the big bang theory. she says that radiation has been detected everywhere equally as heat in the universe and is increasing. this has been shown to be residual radiation from the big bang. what error did the scientist make?