Answer:
The percentage of workers in agriculture is higher than the GDP percentage. This could be because industry and service workers contribute more to output on average.
"<span>a. the size of their military" would be the best option from the list, since they greatly outnumbered the colonists and their militias. They were also far-better trained as soldiers. </span>
Located in South East Asia and approximately 10,000 miles away from the Continental United States the Vietnam climate and geographical plains made it hard to travel and transport supplies.
Much of Vietnam, especially the mountains is covered by dense jungle (The Embassy of the Socialist Republic of Vietnam in the United Kingdom) Has 2 major rivers used largely for transportation.
Southern Vietnam was bordered by Laos and Cambodia and Was divided by the US military into FOUR sections making communication and back up difficult. also, the United States at the time were not trained widely for jungle battle, and were extremely vulnerable for surprise attacks.
The Shang Dynasty wrote on Oracle Bones. Hope his helps ;)