Final answer:
The major river systems in southern Africa, including the Zambezi, Limpopo, and Orange River, do not form easily navigable 'highways into the interior' as they have natural barriers that make navigation difficult, which makes the original statement false.
Step-by-step explanation:
The statement that the major river systems in southern Africa, such as the Zambezi, the Limpopo, and the Orange River, form easily navigable "highways into the interior" of the continent is false. While these rivers were crucial for the development of civilizations and played a significant role in trade and migration, they are not necessarily easily navigable for modern transportation standards.
The geography of southern Africa features significant obstacles such as waterfalls, rapids, and varying river depths that make navigation difficult. For instance, the Zambezi River is known for the Victoria Falls, which is a significant barrier to navigation. Similarly, the Limpopo and Orange rivers have stretches that are not suitable for large-scale navigation. Instead of being easily navigable highways, these river systems served as important avenues for contact and trade among the peoples of southern Africa despite their navigational challenges.