问题补充：
Though Jane speaks Russian well, she thinks it necessary to learn foreign language.
A. the other
B. the second
C. a second
D. other
答案：
A. the other
B. the second
(答案→)C. a second
D. other
解析：a second 指 second foreign language(又一外语), 序数词前加不定冠词,意思是:一,又一.
