Question

Certain birds, such as the flaming or the kori bustard bird, are able to fly because of a certain internal adaptation to their bones. These criss-cross structures allow the bird to be lightweight but still retain bone strength.

Which adaptation makes it easier for birds to fly?

A. gills

B. struts

C. cartilage

D. bone marrow

Answer 1

Struts.
because the bodies of birds are adapted for flying. 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.