Question

give reasons why human cannot respire through diffusion​

Answer 1

Answer:

In order to be a feasible means of providing oxygen to the cell, the rate of oxygen uptake must match the rate of diffusion across the membrane. In other words, if the cell were very large or thick, diffusion would not be able to provide oxygen quickly enough to the inside of the cell.

Answer 2

Answer:

because human beings have complex body structure