皮皮学，免费搜题
登录
搜题
【单选题】
以下关于主键和唯一索引的区别不正确的是?A.
主键顺序为数据的物理顺序
B.
主键：默认将是聚簇索引；唯一索引：默认将是非聚簇索引
C.
主键每个表只能有一个，唯一索引可以多个
D.
主键不能空，唯一索引可以为空
手机使用
分享
复制链接
新浪微博
分享QQ
微信扫一扫
反馈参考答案：
举一反三
【单选题】How long does it take him to walk to the bookshop?
A.
Twenty minutes
B.
Half an hour.
C.
Ten minutes
D.
Forty minutes.
【单选题】-- does it take him to get to school? --About fifteen minutes.
A.
How often
B.
How long
C.
How much
D.
How far
【单选题】【图片】如图所示，VD1、VD2均为理想二极管，下列哪个说法是正确的？
A.
两个二极管VD1、VD2均导通。
B.
二极管VD1优先导通。
C.
输出直流电压Uo为6V。
D.
输出直流电压Uo为-3V。
【简答题】How long does it take him to __________ to the shopping mall? (mind drive survey issue)
【单选题】Did it take him to get through the work?__________
A.
one and a half year
B.
B two Scores of days
C.
several hundred days
D.
four dozens weeks
【单选题】——______ did it take him to draw the horse? ——Half a week.
A.
How much
B.
How often
C.
How long
【单选题】— ______does it take him to come to work by train? — An hour. [ ]
A.
How often
B.
How long
C.
How far
【单选题】_____ does it take him to walk to the park every day? [ ]
A.
How far
B.
How often
C.
How long
D.
How much
相关题目：
【单选题】——______ did it take him to draw the horse? ——Half a week.
A.
How much
B.
How often
C.
How long
参考解析：
知识点：
题目纠错 0
发布
