More than 329 million people live in America and according to the findings of a new study, a fifth of them can’t name a single branch of the federal government.
For scale, that’s roughly 65 million people.
It marked the barrier between Western pro American countries and the USSR controlled communist States
Remote Sensing
Gis would technically be an okay answer too but in this case Remote sensing best fits.
Hey!--- The "Red Terror" is associated with Russia.----Hope this helps! :)