Answer:
The primary reason the US advocated the Open Door Policy was to protect and broaden US trade with China. This policy was put into effect in the early 20th century after the Boxer Rebellion in China. It hastened the end of the last dynasty in Chinese history.
It didn't allow them to settle on land west of the Appalachian mountains.
That was called the Roman Republic. consisting of two Consuls, elected yearly, a Senate, with a life term, and an assembly.
The forceful movement of air.
Answer:
1: South america
2: South america
3: Anglo-America
4: Europe
5: Far East
6: Africa (...? 90% sure here.)
7: The Middle East
<em>I believe I got them all, notify me via comments if I'm right. (do so nicely ofc I didn't mean to get it wrong...)</em>