在数据库的三级模式结构中,内模式有______个。
参考答案:A
用所给词的适当形式填空。
1. How long did he (sneeze)?
2. She wrote a book about the (record) of her life.
3. My brother____(start) learning English in 2006.
4. Deng Yaping is one of the best table tennis (play) in the world.
5. When____(be) Michael Jordan (bear)?
以下哪种肿瘤仅发生于颌骨
A.巨细胞瘤
B.骨化性纤维瘤
C.造釉细胞瘤
D.骨瘤
E.以上都不是