问题
About of the students in our school were born in the .
A:two-thirds, 1990
B:two-thirds, 1990s
C:two-third, 1990
D:two-hird, 1990s;
B:two-thirds, 1990s
C:two-third, 1990
D:two-hird, 1990s;
正确答案是：
