【正确答案】⑴symptoms: progressive respiratory distress within 2-6hr（1分）, tachypnea, cyanosis, intermittent expiratory grunting（1分） ⑵ signs: nasal flaring(鼻扇), （1分）chest retractions(三凹征), （1分）fine rales can be heard,（1分） sometimes systolic murmur can be heard at left border of sternum.（1分）