The primary geographical feature that served as a boundary to westward settlement in 1760 was the Appalachian Mountains, since these were very high and treacherous and gave people very little incentive to cross.
I think you forgot to include the options on your question. But based on what I know about external frustration, it is a behavior that will push an individual to do everything just to achieve its goal which is caused by failures or rejections. <span>I am hoping that
this answer has satisfied your query and it will be able to help you in your
endeavor, and if you would like, feel free to ask another question.</span>
Answer:
That they are caused by earthquakes.
Explanation:
They are caused by the wind.
They are caused by tectonic plates.
The border of Mexico and usa
