What is a primary source? how is that different from a secondary source?

A Primary source is direct information from a person who experienced an event while a secondary source is like an article about a event

Explanation:

Primary source is a direct evidence of a perticular study (consistute direct). Secondary source provides info about a perticular study but does not constitute direct (first-hand evidence).

these two sources are different from each other because, primary sources provides direct account while secondary sources describes, interpret, analyzes.

HOPE THIS IS HELPFUL!!! (:

the graph shows the spread of railways in the 1800s.

based on the graph, the conclusion that can be drawn about germany is answer d)   by 1880, germany had more rail lines than great britain and russia.