The old man kept on studying Chairman Mao’s in his .
A. work . sixty
B. novels, sixtieth
C. works, sixties
D. books, sixty’s
网友回答
A. work . sixty
B. novels, sixtieth
(答案→)C. works, sixties
D. books, sixty’s
解析：第一空表示作品或著作，所以用works; in one’s sixties 意思是：在某人六十多岁。所以C选项符合题意。