What are the best ways to revise... - BBC Learning English

Around 16,000 years ago, the area surrounding Burn O’Vat was covered by a glacial ice sheet 🤯 As the area warmed around 14 000 years ago, the ice sheet began to melt, resulting in a torrent of meltwater that carried with it debris previously caught up in the glacial ice. L This debris, consisting of rocks and boulders, is thought likely to be the most important component of the formation of Burn O’Vat 😮 Approximately 12 000 years ago, the entrance to the vat was exposed when the rock in front