The table below shows the function of some of the body systems.
| Body System | Function |
| A | One part of this system is the longest so the substances take the longest time to pass through it to be broken down. |
| B | One part of this system has hairs that prevent dust particles from entering the body. |
| C | Every part of this system needs to work closely with the muscles to provide movement. |
Which body systems could A, B and C represent?