140. _____, when he was already _____, he started to learn English.

　 A. Is the 1980; thirties　　 　　　　　　　　　　　　　　　　　 B. Is the 1980’s; in his thirties

　 C. Is the 1990, in thirties　　 　　　　　　　　　　　　 D. Is the 1990’s ; in the thirties