The correct answer is sympathetic nervous system.
<span>
The sympathetic nervous system is a component of the autonomic nervous system, together with the parasympathetic system. Their functions are opposite but coordinate to maintain homeostasis. The sympathetic system has a role to control the body's response during perceived threat (fight and flight reactions). According to this, it dilates the pupils, contracts the muscles, increases heart rate...</span>
Essentially, when you breathe in the lung take in oxygen and pass it along to the bloodstream, which brings it to your bodies cells. In return it picks up carbon dioxide, which the lungs dispose of. Every time you breathe this process is happening. That is why it's crucial to keep your lungs healthy.
Glaciers leave behind deposits known as glacial till, which are unstratified, poorly-sorted sediments. Glaciers move a wide range of sedimentary particles from small clay-sized particles to large boulders. When the glacier either melts or retreats, these poorly-sorted sediments are deposited.
Answer:
They digest without the use of teeth.
Explanation:
The food trickles from the crop into the bird's stomach (proventriculus or gizzard) where digestive enzymes are added to the mix and physical grinding of the food occurs. The gizzard is why chickens do not need teeth.