The passage mainly explains

how railways led towns to keep a single, shared time (The passage traces how the railway's need for one time led to standard hours and zones.)

Before railways, how did a town decide when it was noon?

The moment the Sun stood highest overhead (The text says noon was 'the moment the Sun stood highest overhead'.)

The passage suggests that standard time was adopted mainly because it was

practical for running trains safely and on schedule (It calls standard time 'a convenience for trains' and stresses safety on shared tracks, not solar accuracy.)

In this passage, 'adopted' most nearly means

took up and began to use (Nations 'adopted these standard hours' means they took them up and began using them.)

How Railways Set the Clocks: Level 3 Reading Comprehension Questions

For most of history, each town kept its own time. Noon was simply the moment the Sun stood highest overhead, so a clock in one city might read a few minutes different from a clock a short distance away. When people traveled by foot or horse, these small gaps caused no trouble.

The railway changed that. Trains ran on printed timetables, and a timetable makes no sense if every station measures the hour differently. A train might seem to arrive before it left, simply because the two clocks disagreed. Confusion of this kind could also be dangerous, since two trains sharing one track had to know exactly when each would pass.

To solve the problem, railway companies agreed to keep a single, shared time along their lines, ignoring the small differences from town to town. In time, whole nations adopted these standard hours, and the globe was divided into broad zones, each keeping one clock. What began as a convenience for trains became the way the modern world tells time. The Sun no longer sets the hour; a shared agreement does.

Comprehension questions