46.the second radar has no sweeping line

辅助雷达没有扫描线。

About ten o'clock in the morning we came to where this line of rugged hills swept down into a valley, through which flowed the north fork of Red River.

早上大约十点的时候，我们来到高矮不一的一处丛林路口，俯瞰脚下林木直抵山下沟谷，那条红河北段从脚下沟底流过。