The main purpose of the ____________ system is to break food particles into pieces that can be used.

• circulatory
• respiratory
• digestive
• skeletal

What is responsible for delivering oxygen and removing carbon dioxide from the body?

• cell nucleus
• excretory system
• nervous tissue
• respiratory system

The __________ system directs the body to inner and outer changes.

• digestive
• circulatory
• nervous
• skeletal

The __________ is the main organ of the nervous system.

• heart
• lungs
• brain
• skin

The circulatory system uses _________ to deliver oxygen to the rest of the body.

• blood cells
• lungs and nose
• blood vessels
• brain and spinal cord

Which system are the lungs in?

• respiratory
• digestive
• excretory

Which system is the stomach in?

• respiratory
• digestive
• nervous

Where does digestion start?

• stomach
• mouth
• esophagus

This system includes the heart, blood vessels, veins, arteries

• respiratory system
• circulatory system
• nervous system

This system includes the trachea, lungs, air sacs, diapram

• Respiratory System
• Skeletal System
• Nervous System