基因型为AaXBXb的雌果蝇与基因型为AaXBY的雄果蝇交配,后代将产生几种基因型[ ]
A.6
B.8
C.9
D.12
答案:D
25.—How do you find the latest movie by Depp?
—_________.I can’t think too highly of it.
A.It’s really wonderful
B.It all depends
C.No one knows for certain
D.It’s not my cup of tea
将E-R图转换到关系模式时,实体与实体间的联系可以表示成( )。
A.属性
B.关系
C.键
D.域