Did you know that a turtle can lay 12 eggs in one minute? A large sea turtle lays around 150 eggs at a time. She lays all these eggs in just a few minutes. Large sea turtles live in the warm seas of the world. Except for when they lay their eggs, they spend their whole lives in the water. When it is time to lay their eggs, the females  swim to land. They usually return to the place where they themselves were born. How they find their way back there is unknown. When they reach shore, the big, heavy turtles crawl slowly up to the high water mark. Using their flippers, they pull themselves along the sand. They must struggle like mountain climbers. When they finally reach dry sand, they rest before beginning the difficult task of laying eggs. The turtles lay the eggs in deep holes and cover them with warm sand. The sand protects the eggs from harm. Then the females leave them. After a few weeks, if you happened to be walking along the beach, you might see the sand begin to shake. You may see tiny black balls coming out of the sand. The tiny heads of baby turtles! Which sentence expresses the main idea?
Sea turtles have interesting life habits. Sea turtles swim to shore to lay their eggs. Large sea turtles lay their eggs in special ways. Sea turtles enjoy staying in the sand.