The sinuses are O air-filled cavities that secrete mucus to keep the nose moist and remove bacteria.
O tubes at the end of the pharynx that are made of different types of cartilage and muscle, and lined with a mucous
membrane.
tubes that conduct air to the lungs, and allow for gas exchange of oxygen and carbon dioxide.
small, curved, bony plates that line the walls of the nasal cavity, and are covered with a mucous membrane.

O air-filled cavities that secrete mucus to keep the nose moist and remove bacteria.

answer: because barriers look like ball

explanation: there round and blue like my ball

no, because those are both different running competitions. while distance runners train their legs and their lungs to run long amounts of time, the sprinters are training their legs and their lungs to give all they have in the little amount of area they need to cover. the brain also plays a huge part in all of this.

the brain is the only thing in your body that sends messages to your body telling you to run. if you are a long distance runner and you have the mind set of a sprinter, you will not get anywhere. if you have a long distance mind set and you have to run 200m in 20 seconds then you will not make it in time.