Question

which gas is delivered (brought to) different parts of your body by your heart and lungs, that keeps you alive?
nitrogen
oxygen
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Explanation:

The respiratory and circulatory systems (involving heart and lungs) work to deliver oxygen to body tissues for cellular respiration, which is essential for life. Nitrogen is not used for this vital life - sustaining function in the body.

Answer:

The correct option is the one with "oxygen" (the option with the checkmark, likely presented as: The gas delivered to different parts of the body by the heart and lungs to keep one alive is oxygen, corresponding to the option with "oxygen" in the given choices). If we follow the multiple - choice option format as in the problem, it would be the option labeled with "oxygen" (the one with the checkmark in the original image, so in terms of the options: the option with "oxygen" is the correct one, e.g., if the options were A. nitrogen, B. oxygen, then the answer is B. oxygen).