Q: What does the gizzard in birds contain that allows them to grind food?


Read this paragraph and choose the correct option from the provided answers:

The digestive system of birds is unique, with a gizzard that contains swallowed stones for grinding food. Birds do not have teeth. What do you think the stones do? They help them digest their food. Defining characteristics of modern birds also include:.

 Choices:

- acid

- bile

- teeth

- swallowed stones


A:
swallowed stones