Question

A bird flies by moving its wings up and down. Which two systems are most directly responsible for the movement of a bird's wings?

A bird flies by moving its wings up and down. Which two systems are most directly responsible for the movement of a bird's wings?
A.
respiratory and muscular systems
B.
skeletal and digestive systems
C.
respiratory and digestive systems
D.
skeletal and muscular systems

Answer 1

D

Step-by-step explanation:

skeletal and muscular systems