the answer is photosynthesis bcuz plants have to go thru the photosynthesis process to give off oxygen. hope the helps Brianliest??
"The red blood cell<span> survives on average only 120 days. </span>Red cells<span> contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the </span>body<span> and then returns carbon dioxide from the </span>body<span> to the lungs so it can be exhaled." - hematology.org</span>
All the blood types are A+, A-, B+, B-, O+, O-, AB+, and AB-.
