Final answer:
The Nile cataracts were a problem for Kush because they impeded navigation and transportation.
Step-by-step explanation:
The Nile cataracts were a problem for Kush because they impeded navigation and transportation. The cataracts were areas where the river flow was disrupted by waterfalls, shallows, or boulders, making it difficult for boats to pass through. This hindered trade and communication along the Nile, which impacted Kush's ability to engage in commerce and maintain connections with other civilizations.