These temporary observationposts were all within 10 km of the city.
这些临时测点均位于离城10公里以内。
2
The network was not visible from the air, or from ground-level observationposts.
该网络是不可见，从空中，或从地面水平观察哨所。
3
More than through his words, I've learned from observation; from the locations of his ads, the frequency of his posts, and a thousand other details the casual reader would never notice.