Complete these sentences about the circulatory and respiratory systems: Oxygen
Organs
Breathe
Blood
Heart
Mouth
Lungs
Machine
Carbon dioxide
Our body is a complex ____________ . A body system is a group of ____________ that work together. The circulatory system moves the __________ around the body. The most important organ in the circulatory system is the ___________ . Blood gives us nutrients and _____________ . The main function in the respiratory system is help us _____________ . The air enter through our nose and __________ and goes down into our __________ . We breathe in oxygen and breathe out ___________ .