可以用来度量随机变量的波动程度的有()。
A.方差
B.标准差
C.样本方差
D.样本标准差
E.协方差
参考答案:A, B, C, D
解析:协方差是用来表示两个变量是如何相互作用的。
完成英语句子
1. (有)two maps and some pictures on the wall.
2. Her father (没有) any sister.
3. (有) some water in the cap.
4. —What's his (爸爸的) job?
—He is a teacher.
5. I can see (十九) students in the classroom.
6. Tom's school is a beautiful school and it's (英语) school.
该患者病情平稳后一直应用地高辛,一天发生腹泻后出现心动过缓,心率84次/分,二度房室传导阻滞,应该
A.停用地高辛,补钾
B.临时起搏器
C.应用阿托品
D.停用地高辛,应用苯妥英钠
E.应用甲氧胺