Name two adaptations that allow birds to fly.

Light, hollow bones. Strong lungs.

Many of a bird's bones are less dense than human bones, which makes birds' bodies lightweight. Flying birds have large chest muscles that move the wings. Birds have feathers that help them fly. The long flight feathers on the wings and tail help birds balance and steer.

Explanation:

an expansion is one of two basic business cycle phases; the other is contraction. the transition from expansion to contraction is a peak, and the changeover from contraction to expansion is a trough.

d. promised it other land