<u>Answer:</u>
By 1775 more than a half-million African Americans, most of them enslaved, were living in the 13 colonies.
The lengthening of the barrel and the transition from muskets to rifles.<span> The longer barrel helped with accuracy. With rifles, the US could fire at the British from a safe distance and with accuracy.</span>
Had to look for the other options and here is my answer.
Based on the options given which are <span>complex civilization, </span><span>surplus of food, </span><span>division of labor, and</span><span> domestication of plants and animals, I can say that the feature of the agriculture of Chinese that led to the development of the other three would be the domestication. Through domestication, they were able to cultivate for food. Hope this helps.</span>