在SQL中，由于对视图的修改最终要转换为对基本表的修改，因此下列只有哪种视图是可以修改的？（）
A. 行列子集视图
B. 带表达式视图
C. 分组视图
D. 连接视图
查看答案
German technology conglomerate Siemens showed its new mobile phones
A. at a news conference.
B. at a mobile trade show.
C. at a mobile handset unit.
D. at a mass market.
What does the man mean
A. It would be best to drop both.
B. Steve's part-time jobs are the best for him.
C. Steve is really working too hard.
D. Steve's decision may be a good on
Ageism is different from other "isms", because of all the following reasons EXCEPT that
A. it is based upon the constant age classification.
B. the concept of agedness is changing gradually.
C. one is experiencing the aging process oneself.
D. age classification remains the same for many years.
Generation X
A. will experience a poorer living standard soon.
B. is experiencing a poorer living standard now.
C. may experience a poorer living standard.
D. may not experience a poorer living standar
微信支付 
支付宝支付