A、Encouraging international exchange. B、Creating single-sex classrooms. C、Ensuring gender equality. D、Employing women teachers.

(23)Scientists have previously believed that the relatively low numbers of women in high-level mathematics could be due to biological differences between men and women. But a new, international study has cast doubt on the idea that the differences are biological at all. Previous studies tended to focus on a limited range of countries—whereas the new study observed school-level mathematical performance in 86 countries.(24)According to the study, the poor performance in women’s mathematics seemed to be caused by social factors—i. e. each society’s attitude to women. The study suggests that boys—as well as girls—tend to do better in maths when raised in countries where females have better equality, and that’s new and important. It makes sense that when women are well-educated and earn a good income, the maths scores of their children of both genders benefit. None of the findings suggest that a biological difference between the sexes is the primary reason for a gender gap in math performance at any level. Rather, these major international studies strongly suggest that the maths gender gap, where it occurs, is due to cultural factors that differ among countries -and that these factors can be changed. One proposed solution, creating single-sex classrooms, is not supported by the data.(25)Instead, researchers recommend increasing the number of math-certified teachers in middle and high schools, decreasing the number of children living in poverty and ensuring gender equality. These changes would help give all children a chance to succeed.
23. What did scientists believe in the past?
24. What leads to women’s poor performance in mathematics according to the new study?
25. According to researchers, what can be done to improve women’s mathematical performance?