Once a year , people take part in “ Lights ” activity to help save energy .
A. Show Off
B. Turn Off
C. Take Off
D. Put Off
网友回答
A. Show Off
(答案→)B. Turn Off
C. Take Off
D. Put Off
解析：根据to help save energy“帮助节约能源”可知，本题意思是“关灯”以节约能源，所以应该用turn off。其他选项不符合题意，故排除。所以本题选B。