题目

I’ve tried very hard to improve my English.But by no means with my progress.  A.the teacher is not satisfied B.is the teacher not satisfied C.the teacher is satisfied D.is the teacher satisfied 答案：D甲、乙两位同学参加跳高训练，在相同条件下各跳10次，统计各自成绩的方差得S甲2<S乙2，则成绩较稳定的同学是（    ）。（填“甲”或“乙”）