The best reason I can think of for why we believe that air is a mixture is that freezing air slowly yields different liquids at different temperatures. Liquid nitrogen has a different boiling point than liquid oxygen. They also freeze at different temperatures.
An inguinal hernia is a protrusion of abdominal-cavity contents through the inguinal canal. Symptoms are present in about 66% of affected people. This may include pain or discomfort especially with coughing, exercise, or bowel movements. Often it gets worse throughout the day and improves when lying down.
A groin (inguinal) hernia occurs when part of the intestine bulges through a weak spot in the abdominal wall at the inguinal canal. The inguinal canal is a passageway through the abdominal wall near the groin. Inguinal hernias are up to 10 times more common in men than in women. About one in four men develop a hernia at some point in life.