Which best describes a development that improved railroad safety? Railroads adopted standard time to coordinate schedules.
Railroads offered fold-down beds so that people could sleep more comfortably.
Companies standardized track technology so that they could use each other’s tracks.
Companies replaced hand-operated brakes with air brakes on trains.

The answer should be: Companies replaced hand-operated brakes with air brakes on trains.

Explanation:

You have to think how hard it was for trains to stop with hand operated brakes. Trains go fast, and not stopping in time can be dangerous. Hope this helped :)

photos creat an ovveral image of the civil war

yes based on alexanders actions he deserved the title of "the great". his empire covered about 3,000 miles and he was able to establish the empire over a 13 year period of time. he was able to conquer many different places. he also defeated the persians. he conquered egypt and developed a city and named it after himself.