Houses on opposite sides of the street is an example of across.
Across the street.
To walk over a bridge is an example of to walk across.
All across the country, voters were communicating their representatives.
A bridge across a river.
Came across my old roommate.
The footbridge swayed when I ran across.
We came across by ferry.
Drew lines across the paper.
If we sail off at noon, when will we be across?
I got stuck on 4 across.
Put our idea across; get a message across.
Seated with arms across.
That store is across the street.
Lay the top stick across the bottom one.
She had straps fastened across the conduit every six feet.
Origin of across
From American Heritage Dictionary of the English Language, 5th Edition