Q: What important and unusual physical property (for birds) do ostriches and penguins share? Read this paragraph and choose the correct option from the provided answers: There are about 10,000 living species of birds. Almost all of them can fly. Flying birds are classified in 29 orders. Most species belong to the order of perching birds. A few birds are flightless, such as the ostrich and penguin, but they evolved from a flying ancestor. Choices: - waterproofness - webbed feet - bonelessness - flightlessness A:
Answer:
flightlessness