问题
About ___of the workers in the factory were born_____.
A:two thirds,in the 1970
B:two thirds,in the 1970s
C:two third,in the 1970
D:second thirds,in the 1970s
B:two thirds,in the 1970s
C:two third,in the 1970
D:second thirds,in the 1970s
正确答案是：
