Hearing the doctor announce their son was safe and sound, the couple sighed with .
A. satisfaction
B. relief
C. interest
D. permission
网友回答
A. satisfaction
(答案→)B. relief
C. interest
D. permission
解析：A. satisfaction满意，B. relief缓解，宽慰，C. interest兴趣，D. permission允许，句意：听到医生宣布儿子安然无恙，这对夫妇宽慰的松了口气。所以选B。