Spiracles are holes in butterflies that allow air to pass into their air tubes. The tracheae then circulates the oxygen and the heart circulates the blood.
fishes do have parallel circulation
exoskeleton
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Pulmonary circulation Pulmonary circulation pulmonary circulation pulmonary circulation
Hemoglobin molecules function as the carrier in the human blood circulation system.
respiration system and circulation system
Poultry Circulation System
Blood circulation takes oxygen to your system---(circulation)
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Circulation system, respiratory system, excretory system, reproductive system, etc.
Not enough information circulation from where to where? see discuss
circulatory system