The First correct answer is: "In both territories, settlers from differents U.S. regions engaged in widespread conflicts over the issue of slaver". The U. S. territory expansion fueled the debate of slavery because the rapid expansion took place to a mistreatment of native american and hispanic occupants.
The Second answer is, following the Manifiest destiny, while Texas was addmited to the Union as a state, the firmed idea was to expand to the Pacific Ocean and to take among all territory, urging national unity on behalf of “the fulfillment of our manifest destiny to overspread the continent allotted by Providence for the free development of our yearly multiplying millions.”
This is a question about geography. A "strait" (not "straight") is a narrow body of water that acts as a passageway between one larger body and another. In your shoes I would look up "Constantinople location" on the Internet.
It was important because it enabled countries to make steel cheaply and this was then used to make better tools and better machinery and it enabled the industry to prosper. This forced them to become imperialistic in order to get more resources to increase the scope of the revolution even more.