The invention of the (blank) made harvesting wheat on a large scale possible. A. McCormick reaper. B. john deer steel plow.
C. harvest blaster.
D. elevator.

b

Explanation:

isolationism is a doctrine practiced by the united states for much of its history with the aim of not intervening in external affairs that did not pose a real threat to their country. the united states managed to maintain a state of political isolation throughout the nineteenth century and the first part of the xx. few nations have been able to maintain such a position for such a long period of time. historians argue that it is largely due to geographical reasons, given the physical distance between europe and the usa. uu the venataja of this situation is that the national state can spend its resources in satisfying all the needs of its inhabitants, without the need to invest in armament and equipment for a war that does not directly affect the country.

internationalism is a political and cultural movement that advocates for greater political and economic cooperation among nations for mutual benefit. this novimiento was transformed over time, today it includes military intervention in international conflicts with the objective of maintaining peace. the advantage of this move is in the international contacts and the influence developed by the country that carries it forward.

between the two modes of relations between states, i prefer the first, since i believe it is of the utmost importance to satisfy the needs of citizens and work for their development and as a last option to act on the international level.

the use of email to replace slower surface mail.