The year is based off of Earth’s revolution around the sun. 1 year is equal to the amount of time that it takes for Earth to revolve once around the sun.
Your answer is Enamel it is the coating on teeth that helps prevent damage.
The seasonal movement of animals from one place to another (usually occurs in species with ability to flight and in large amount
The pituitary gland secretes a hormone called antidiuretic hormone (ADH) which reabsorbs water in the kidney from the urine