Long TextExercise 25 of 74

Ten thousand years ago, as the last ice age drew to a close, sea levels around the world were far lower than they are today. Much of the land under both the North Sea to the east of Britain and the English Channel which now separates France and Britain was part of a huge region of forests and grassy plains, where…

• What point is made in the first paragraph about the area now under the sea?
• How does the new sonar technology work?