兰州，是西北地区政治经济文化的中心，又自古是控扼河西走廊、青海、宁夏的交通要冲，丝绸之路从这里经过。奔腾咆哮的黄河，自西向东，横贯金城，将本已过于狭长的谷地切割成更窄的南北两条。黄河天堑给南北交流带来巨大障碍，使只有一箭之遥的河北经济长期处于相对落后的状 Lanzhou is the political, economic and cultural center of Northwest China. Since ancient times, Lanzhou passed the Silk Road through the control of the Hexi Corridor, Qinghai and Ningxia. Growing Pentium roaring Yellow River, from west to east, across Jincheng, the already too narrow valley cut into two more narrow north-south. The natural moat of the Yellow River brought great obstacles to the exchanges between the North and the South, leaving only a stone’s throw of Hebei’s economy in a relatively backward state