Section: Paragraph Comprehension

Question 1 of 15

1) There are several differences between reptiles and birds. One key difference involves the skeletal structure between the two and the fact that birds have wings. Reptiles have solid bones that are dense and they travel on land or in the water. Birds have hollow or pneumatic bones filled with air that are lighter and allow them to fly. In addition, birds have a lightweight beak instead of teeth, or a heavy jaw.