单项选择题
A．because they lay their eggs in mountain areas B．to give you a picture of how hard they work C．to tell you that they like to climb D．to tell you that mountain climbers are as slow as turtles
A．to keep them cool B．to protect them from danger C．because of deep instinct D．to protect them from the weather
A．turtles B．oceans C．time D．eggs