题目内容

Nowhere but around this mountain area ______ such kind of custom in the past twenty years.

A. [A] we found
B. [B] we had found
C. [C] did we find
D. [D] have we found

查看答案
更多问题

某研究比较分析了过去接触氯乙烯和未接触氯乙烯女工目前妊娠结局情况,此研究属于

A. 回顾性研究
B. 回顾性队列研究
C. 队列研究
D. 横断面研究
E. 实验性研究

It's incredible that France ______ the EU Constitution.

A. [A] rejects
B. [B] rejected
C. [C] has rejected
D. [D] should have rejected

将10名研究对象编号,然后从随机排列表中任选一行数字,取个位数,凡对应随机排列中偶数者为甲组,奇数者为乙组,这种分组方法为

A. 随便分组
B. 简单随机分组
C. 分层随机分组
D. 整群随机分组
E. 联合随机分组

若用如下的SQL语句创建一个表S: CREATE TABLE S(S# Char (16) NOT NULL; SNAME char(8) NOT NULL,SEX char(2),AGE integer)向表S中插入如下行时,哪一行可以被插入

A. ('991001','李明芳',女,'23')
B. ('990746','张民',NULL,NUL
C. (NULL,'陈道明','男',35)
D. ('992345',NULL,'女',25)

答案查题题库