The circulatory system - hemoglobin in the blood transports oxygen :)
Explanation:
A dichotomous key is a tool that allows the user to determine the identity of items in the natural world, such as trees, wildflowers, mammals, reptiles, rocks, and fish. Keys consist of a series of choices that lead the user to the correct name of a given item. "Dichotomous" means "divided into two parts".
Answer:
i believe it is A: air because carbon comes from air so if they take in the air to maike it they are also taking in carbon
Explanation: