<span>One ounce of beef liver provides more than three times the RDA for vitamin A. The answer to the blank space is beef liver. Beef liver is rich with vitamins especially the vitamin A. The cow's beef is healthy for the human health but it should be eaten moderately.</span>
Collagen
is a protein fiber that is found in the matrix that lies outside the bone
cells. Population of these collagen fibers that scattered through the matrix are
embedded in a gel-like ground substance called hyaline cartilage, which
is flexible but avascular and contains no nerves or blood vessels.
