Why do you need only one polio vaccination, but a new flu shot every year?

In which process is oxygen absorbed by an organism asap apex

Which of the following statements most accurately describes convergent evolution? the process in which two similar species evolve separately from each other and share similar characteristics the process in which a single species evolves into two or more new species the process in which two entirely different species evolve in response to each other the process in which two different species evolve separately from each other but still share similar characteristics

What drives the atp synthase reactions that produce atp