Answer:

a.Brain

• The control center of the body is the brain. The brain controls all of our actions and functions, both voluntary and involuntary. Our brain is a major part of our nervous system, which also includes nerves and our spinal cord.

b.musculoskeletal system

• It provides form, support, stability, and movement to the body. The musculoskeletal system is made up of the body's bones (the skeleton), muscles, cartilage, tendons, ligaments, joints, and other connective tissue that supports and binds tissues and organs together.

c.chemical digestion

• As food travels from your mouth into your digestive system, it's broken down by digestive enzymes that turn it into smaller nutrients that your body can easily absorb. This breakdown is known as chemical digestion.

d.The circulatory system

The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.

e.Lungs

• What Are the Lungs and Respiratory System? The lungs and respiratory system allow us to breathe. They bring oxygen into our bodies (called inspiration, or inhalation) and send carbon dioxide out (called expiration, or exhalation).