Question

why grass eating animals can digest cellulose whereas human beings cannot?​

Answer 1

Answer:

Because they are animal we are human

Answer 2

Answer:

Humans lack the enzyme necessary to digest cellulose. Hay and grasses are particularly abundant in cellulose, and both are indigestible by humans (although humans can digest starch). ... The bacterial digestion of cellulose by bacteria in the stomachs of ruminants is anaerobic, meaning that the process does not use oxygen.