My laptop glitched, this isn’t the question I meant to answer sorry:)
For 18, i'd say D.
For 19, i'd say D.
Diffusion and Colonization/Migration of agricultural peoples
The main reason why American soldiers used Agent Orange was to eliminate the forrest coverings in Vietnam during the war, in order to eliminate the hiding spots of the enemy.
by which time sea routes were replacing the Silk Roads. -- "The Silk Road" is an extensive intercontinental network of trade routes across the Asian continent connecting East, South, and Western Asia with the Mediterranean world, as well as North and Northeast Africa and Europe (and thus a network linking Eurasia).