避雷器出厂试验验收中，哪些试验项目没有作具体规定，需符合合同与投标文件的要求（）。

A.持续电流

B.工频参考电压

C.直流参考电压

D.密封试验

The proportion of women among students enrolled in higher education programs has increased over the past decades. This is partly shown by the fact that in 1959, only 11 percent of the women between twenty and twenty-one were enrolled in college, while in 1981, 30 percent of the women between twenty and twenty-one were enrolled in college.
To evaluate the argument above, it would be most useful to compare 1959 and 1981 with regard to which of the following characteristics

A．The percentage of women between twenty and twentyone who were not enrolled in college.

B．The percentage of women between twenty and twentyfive who graduated from college.

C．The percentage of women who, after attending college, entered highly paid professions.

D．The percentage of men between twenty and twenty-one who were enrolled in college.

E．(E) The percentage of men who graduated from high school.