Bones are hard structures and cannot be bent but we still bend our elbow, knee etc. How is this possible?

Bones are hard and cannot bend on their own. The joints help the body in moving. Muscles are like elastic bands which are attached to the bones by means of tough connecting bands called tendons. Muscles help in the movement of bone through pull/contraction.

Explanation:

common management practices in dairy and poultry farming are: (i) proper shelter facilities and their regular cleaning. (ii) some basic hygienic conditions such as clean water, nutritious food, etc. (iii) animals are kept in spacious, airy, and ventilated place.