The Singapore Arms and Flag and National Anthem Rules define the flag's composition and the symbolism of its elements: red symbolises universal brotherhood and equality of man and white pervading and everlasting purity and virtue. The moon represents a young nation on the ascendant.
Normal The bronchial breath sounds over the trachea has a higher pitch, louder, inspiration and expiration are equal and there is a pause between inspiration and expiration. There are two normal breath sounds. Bronchial and vesicular. Breath sounds heard over the tracheobronchial tree are called bronchial breathing and breath sounds heard over the lung tissue are called vesicular breathing.
It is the crackling sound heard with a stethoscope when placed over the lungs. It is hard to describe it. If you google it you may find how it sounds like but a close one would be the sound you hear when you rub your hair close to your ears. It is mostly abnormal. There are many lung and heart diseases which cause it. It is caused by fluid or inflammatory exudate in the alveoli or bronchioles. It could also be caused by fibrosis or scarring of lungs which has many causes. Broadly the causes are infections, fluid in the lungs, cancers, inflammations, etc.