Final answer:
A pelican's lower bill is made of stretchy skin that expands to carry up to three gallons of food.
Step-by-step explanation:
The statement that a pelican's lower bill is made of stretchy skin that expands to carry up to three gallons of food is true. The lower bill of a pelican is unique and can stretch and expand like a pouch to hold large quantities of fish or other food. This adaptation allows them to catch and store fish while swimming.