The Sahara desert is twice as old as we thought. A new report from a climate research centre (1) _____ it is seven million years old. Researchers worked out that a lot of North Africa became desert seven million years ago. A sea started to dry, so there was (2) _____ rain. This helped to make sand dunes, and started the Sahara.

The Sahara is a (3) _____ and big desert. It covers 10 per cent of Africa, from the Atlantic Ocean (4) _____ the Red Sea. A researcher does not think the Sahara is so old. He said the new report has no facts. He said nothing in the Sahara is older (5) _____ 500,000 years old. We only know about the Sahara's climate from 10,000 years ago.