Describe how there was a diffusion of crops along trade routes in afro-eurasia

Improved commercial practices led to an increased volume of trade and expanded the geographical range of existing trade routes—including the Silk Roads, trans-Saharan trade network, and Indian Ocean—promoting the growth of powerful new trading cities

Explanation:

roosevelt believed that in light of the country's recent military successes, it was unnecessary to use force to achieve foreign policy goals, so long as the military could threaten force. this belief, and his strategy of “speaking softly and carrying a big stick,” shaped much of roosevelt's foreign policy.