问题补充:
It came as a great to the parents that their son finally came back safe and sound.
A. favor
B. sense
C. relaxation
D. relief
答案:
A. favor
B. sense
C. relaxation
(答案→)D. relief
解析:A. favor恩惠,帮助,B. sense感觉,C. relaxation放松,D. relief 宽慰,缓解,根据句意:儿子安然无恙的回来对父母是个安慰。所以选D。