【判断题】【消耗次数：1】
关系数据模型的特点是数据结构单一和采用集合运算，而没有数学理论支持。
①
正确
②
错误
参考答案：
复制
纠错
相关题目
【简答题】
传统的数据模型分类，数据库系统可以分为三种类型：[填空]、网状数据库模型和关系数据模型。
随机题目
【单选题】
13. The supervisor appreciates ______ so hard in the office.
①
for your working
②
your working
③
you to work
④
for you to work
【单选题】
10. ______, he was unable to make much progress.
①
Hard as he tried
②
Though hard as he tried
③
He tried hard
④
Because he tried hard
【单选题】
9.She does not_____ that she owes the money, but she just wouldn’t like to return it.
①
argue
②
. dispute
③
think
④
agree
【单选题】
9. By 2008, Beijing ______ its total discharge of pollutants.
①
will reduce
②
will have reduced
③
reduces
④
has reduced
【单选题】
5. The children were seen _______ musical instruments across the street.
①
play
②
to play
③
playing
④
played
【单选题】
8. ______, he was honest.
①
As he was poor
②
Being poor
③
Poor as he was
④
He was poor
【单选题】
12. I’m very sorry to have _______ you with so many questions on such an occasion.
①
interfered
②
offended
③
impressed
④
bothered
【单选题】
7. It is so quiet that you can hear a pin ______.
①
dropping
②
. dropped
③
drop
④
drops