按上、下行方向列车数目划分,运行图分为()。
A.平行运行图和非平行运行图
B.成对运行图和不成对运行图
C.连发运行图和追踪运行图
D.单线运行图和双线运行图
参考答案:B
下列关于SQL对表的定义的说法中,错误的是( )。
A. DownUpClick
B. ClickDownUp
C. DownClickUp
D. UpDownClick
published fifty years ago, his work still attracts much attention at present.
A.As
B.Though
C.Apart from
D.Despite