The main problems of evidence in dealing with early civilizations is that much of the potential evidence itself--such as tools, homes, etc--has vanished due to the fact that it was made of materials such as clay that could not withstand the test of time and weather.
First, take the year that is most recent which in our case is 1973 and then subtract from that 1961 to get 12 years old. Hope this helps!
The answer would be <span>A. to prevent a communist takeover of South Vietnam</span>
"Red Army" is slang, I believe
