伤寒患者解除隔离的条件为()
A.症状完全消失
B.体温复常半个月
C.嗜酸性粒细胞复常
D.连续2次粪便培养阴性
E.肥达反应转阴
参考答案:A, B, D
用所给单词的适当形式填空。
1. I send____ (a) e-mail to my friend.
2. Look at these____ (picture).
3. There is a letter on____ (paper).
4. Li Ming____ (need) a stamp for his letter.
5. How much____ (be) the stamps?
样本指标与总体指标的差别称为抽样误差。