Input (grade 13): The surrounding Kalahari Basin covers over 2500000 k extending farther into Botswana, Namibia and South Africa, and encroaching into parts of Angola, Zambia and Zimbabwe.
Output (grade 10): The surrounding Kalahari Basin covers over 2.5 million kmÂ extending farther into Botswana, Namibia and South Africa, and encroaching into parts of Angola, Zambia and Zimbabwe.