读图技能：读“某地区等高线图”，链接所学知识，回答下列问题．

（1）写出图中字母所在的地形部位名称：A______；B______．

（2）途中ABCD四地可能发育河流且河流流向大致是自东向西流的是______．

（3）图中E地位于A地的______方向．

（4）甲乙两城镇的图上距离是4厘米，则其实际长度是______千米．

-- How are you planning to travel to Shanghai?

　--- I ______ yet, but I ______ taking a train.

A．didn’t decide; am considering

B．haven’t decided; consider

C．haven’t decided; am considering

D．hadn’t decided; have considered