Multiple Choice, Multiple Answers (Reading) — practice #rmcma-001

The Sahara has not always been a desert. Geological and fossil evidence shows that, between roughly eleven and five thousand years ago, much of North Africa was a green landscape of lakes, grassland and rivers. Rock paintings from the period depict cattle, hippos and human swimmers, scenes impossible in today's arid climate. Scientists attribute this 'Green Sahara' to small, cyclical changes in the tilt of the Earth's axis, which strengthened the seasonal monsoon and drew rainfall far inland. As the planet's orientation gradually shifted again, the rains retreated, vegetation died back, and within a few centuries the region returned to the desert we recognise. Researchers note that this drying was not perfectly steady; it appears to have happened in uneven pulses rather than a single smooth decline.