I am not so sure how to use "across" in this situation.
(1) Can I say
The bridge is across a river.
Can "across" directly fellow after "be"?
Black bridge (black stickin the bild) is across the senond grass (green rectangle, there are four regions of grass).
If I say it like above, whether others misunderstand that the black bridge is only across region 2 and no others. But actually, it is also across region 3 and 4. If it is wrong, how can I describe that the black bridge is "across" region 2?