Summary of the sample size (N) and sample distribution according to group, high school, gender and elective, where Bio means Biology and Tech means Technical Drawing, for each group of students.

Summary of the sample size (N) and sample distribution according to group, high school, gender and elective, where Bio means Biology and Tech means Technical Drawing, for each group of students.各学生群体的样本量（N）及按群体、就读高中、性别与选修科目划分的样本分布情况汇总；其中Bio指代生物学（Biology），Tech指代技术绘图（Technical Drawing）。