Valve created by soft palate keeps food out of nasal airway during swallowing
The ductus arteriousus is a blood vessel that connects the pulmonary artery to the descending aorta. Otherwise known as the ductus Botalli, this structure pumps blood into the fetus' non-functioning lungs from the right ventricle. This blood vessel will close at birth and becomes the ligamentum arteriousum.
Isotonic solution.
Since it has the same salt concentration as the cell the solution is neither hypotonic or hypertonic.
Answer:
<em>The tyres of car wear out gradually, due to the frictional force. Frictional force arises between two objects when they move over one another. In the given cases it arises between the tyre and the surface which it is travelling on.</em>