7.下列何種呼吸音為上呼吸道狹窄所導致？
(A)爆裂音（crackles）
(B)哮鳴音（wheezes）
(C)喘鳴（stridor）
(D)粗捻音（crepitation）

呼吸循環物理治療 四版 P239

補充D選項
https://www.osmosis.org/answers/crepitus

The causes of subcutaneous crepitus (皮下捻髮音) usually involve conditions that cause subcutaneous emphysema(皮下氣腫) (i.e., air present in the tissues in the skin), like a pneumothorax(氣胸) ( i.e., collapsed lung(肺塌陷)) or a rupture or tear in the airway or esophagus(氣道、食道破裂/撕裂) (i.e., the tube that transports food from the mouth to the stomach). 

Crepitus can also be heard in individuals who are on mechanical ventilation, a machine that helps with breathing; this would occur if air is present in the mediastinum (i.e., area of the chest that contains the heart) after escaping from the lungs. It can also sometimes be heard in individuals who have experienced chest trauma, like a penetrating wound or blunt trauma. 

When air leaks out of the lungs, like with a collapsed lung, the air can collect in the subcutaneous tissues of the neck and chest, causing subcutaneous emphysema. Crepitus occurs when pressure is applied to the affected area, causing the trapped air to produce popping sounds or a crackling sound.