有一个时期，德国轰炸机主要是靠无线电定向信标来导航的。

For some time the German bombers had navigated largely by radio beacons.

youdao

有一个时期，德国轰炸机主要是靠无线电定向信标来导航的。

For some time the German bombers had navigated largely by radio beacons.

youdao