“Help”.... I think suits to complete it
Exoskeleton and Endoskeleton
Multicellular organisms e.g. man meet their needs through use of specialized systems that they have in their bodies. Examples of such include:
1. cardiovascular system composed of heart, veins and arteries which facilitate transport of nutrients to all parts of the body .
2. Skeletal system composed of bones, joints, ligaments and cartilage whose function is support and protection of the body. <span>
3. Digestive system composed of mouth, esophagus, stomach , small and large intestines whose function is breakdown of food and absorption of nutrients.</span>
i think the answer is d sterilization
It enters the heart via the pulmonary veins
