Final answer:
The Sahel desert stretches across Africa from east to west, while the other statements are not true or partially true.
Step-by-step explanation:
The correct statement about Africa's geography is that the Sahel desert stretches across the continent from east to west. The Sahel is a transitional zone between the Sahara desert to the north and the savannas to the south.
The statement that rivers are navigable from the interior to the sea is not true. Many of Africa's rivers have rapids, waterfalls, or are interrupted by dams, making navigation difficult.
The statement that the savannas are hospitable is partially true. Savannas are open grassland regions that support a diverse range of wildlife and vegetation, but they can also experience seasonal droughts and wildfires.
The statement that the tsetse lives in the Kalahari desert is not true. The tsetse fly, which is known for transmitting sleeping sickness, is mostly found in parts of sub-Saharan Africa, including areas near rivers and lakes.
Learn more about Africa's geography