题目

 Pointing to the house on       roof grew lots of bush, the old man told me that was       I would stay.    A. its; what             B. whose; where         C. whose; what           D. its; where 答案： B测量某一距离，发生的误差X是随机的，并且从样本分析知X的方差是4，求在三次测量中至少有一次误差的绝对值超过4的概率.