允许在嵌入的SQL语句中引用宿主语言的程序变量,在引用时()
A.直接引用
B.这些变量前必须加符号"*"
C.这些变量前必须加符号":"
D.这些变量前必须加符号"&"
参考答案:C
主根上长出的根叫侧根,侧根上长出的根叫须根。 [ ]
________ his arrival, he began to make preparations for the speech of the conference.
A.In
B.With
C.On
D.By