There are two of us and we never touch each other. We work together all day and night. We take in the invisible and give back the invisible. What are we?

Question

Accepted Answer

Lungs. The two lungs sit side by side separated by the heart and never actually touch. They work in constant rhythm, inhaling oxygen and exhaling carbon dioxide — both invisible.

"There are two of us and we never touch each other. We work together all day and night. We take in the invisible and give back the invisible. What are we?"

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