the opposing surfaces of bones that are connected via synovial joints are covered with a thin layer of .

hi~~

i would say that hybridization occurs frequently in nature, because there are many types of hybrids that have occurred naturally, such as the mule (male donkey + female horse)

there is not 1 highest source of protein, but there are many; meats, fish, poultry, seafood, cheese, eggs, yogurt and milk. the only non complete animal food that is beneficial is gelatin.

sorry if this did not , have a great day!