序抗日战争自卢沟桥事变后不久,全国一万多公里海岸线上所有港口都遭日寇封锁或强占。为了维持美英路线的交通运输,只有向西南邻邦借用港口及港口腹地交通路线。同时,中国自己必需修筑必要的路线与借用路线相衔接。第一个借用港口是越南的海防。借用陆上路线有两条:一是海防—? Shortly after the Marco Polo Bridge Incident, all the ports on the coast of more than 10,000 kilometers across the country were blocked or seized by the Japanese invaders. In order to maintain the transportation between the United States and the United Kingdom, only the traffic routes in the hinterland of the port and port are to be borrowed from the neighboring countries in Southwest China. At the same time, China itself must construct the necessary route to connect with the borrowing route. The first borrowed port is Haiphong in Vietnam. There are two ways to borrow land routes: First, Haiphong -?