所谓关系是指( )。

A．各条记录中的数据彼此有一定的关系

B．一个数据库文件与另一个数据库文件之间有一定的关系

C．数据模型符合一定条件的二维表格式

D．数据库中各个字段之间彼此有一定关系

You are passing the Bayou Sara gage which reads 3.9 feet. Which of the following statements is TRUE?（）

A.The river level is above the Low Water Reference Plane

B.Red Store Landing Revetment is ahead on your starboard side

C.This gage reading is at a lower elevation than the same reading on the gage at Head of Passes

D.None of the above