Mr.Morgan can be very sad＿＿，though in public he is extremely cheerful．
A. by himself
B. in person
C. in private
D. as individual
网友回答
A. by himself
B. in person
(答案→)C. in private
D. as individual
解析：通过后半句的转折词though和对比词in public…cheerful来确定sad in private，意思是“私下里”。