When we returned from the ball, we found that our house ___ and many things __

A．has broken into; has been stolen

B．has broken into; had been stolen

C．had been broken into; stolen

D．had been broken; stolen

某校八年级甲、乙两班学生在一学期里的多次检测中，其数学成绩的平均分相等，但两班成绩的方差不等，那么能够正确评价他们的数学学习情况的是[ ]

A.学习水平一样

B.成绩虽然一样，但方差大的班学生学习潜力大

C.虽然平均成绩一样，但方差小的班学习成绩稳定

D.方差较小的学习成绩不稳定，忽高忽低