Question

what are the three main characteristics that are unique to birds? they have feathers, light and hollow bones, and the ability to fly. they have feathers, wings, and the ability to fly. they have wings, light and hollow bones, and the ability to fly. they have wings, light and hollow bones, and feathers.

Explanation:

Flight is not unique to birds (e.g., bats, insects can fly). Feathers, hollow lightweight bones, and wings are traits that are uniquely associated with birds and define their biological identity.

Answer:

D. They have wings, light and hollow bones, and feathers.