About of the workers in the factory were born in the .A. two-thirds 1970B. two-thirds 1

问题补充：

About of the workers in the factory were born in the .

A. two-thirds, 1970

B. two-thirds, 1970s

C. two-third,1970

D. two-third, 1970s

答案：

A. two-thirds, 1970

(答案→)B. two-thirds, 1970s

C. two-third,1970

D. two-third, 1970s

解析：基数词+序数词的复数形式（基数词大于1），in the 年的复数形式表示在…年代，故选B