按照一定的顺序,机械地每隔一定数量的单位抽取一个单位进入样本的抽样方法称为
A.单纯随机抽样B.系统抽样C.分层抽样D.整群抽样E.多级抽样
参考答案:B
用所给动词的适当形式填空。
1. He _______ (not go) camping next week because he _______ (study) for exams.
2. My cousin _______ (finish) school next month.
3. _______ you _______ (go) to the zoo tomorrow?
4. What _______ you _______ (do) these days? I _______ (learn) English.
5. _______ he _______ (play) computer games at the moment?
6. _______ your brother _______ (come) tonight?
7. Look! The monkey _______ (eat) a banana.
8. There _______ (be) a man in the office.
9. The shop _______ (open) at 8:00 a.m.
10. _______ (be) there any toys in the shop?
患者,男性,58岁。右腰痛2年,无痛性全程肉眼血尿3天,查:右肾区叩痛,右肾可触及季肋下3指,尿常规:红细胞充满/HP,肾盂静脉造影可见右肾中盏移位拉长变形,应诊断
A.肾癌
B.肾囊肿
C.肾结核
D.肾盂癌
E.肾胚胎瘤