L Pretest: Unit 3 Question 14 of 32
Cross sections of different areas of the same plant show cells with very
different structures. What does this tell you about the different areas?

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems