Which is the best example of a primary source document useful in the study of history? a. a documentary with expert analysis of the event in question b. a peer-reviewed article written about the event by a respected historian c. a professorial analysis of key battlefield strategies of the event d. a journal excerpt from a person involved in the event in question

D. a journal excerpt from a person involved in the event in question

Explanation:

Historical sources constitute the raw material of History. They include all the documents, testimonies or objects that transmit us significant information regarding the events that have taken place, especially in the past. Within them, and considering the value that others also have, the written sources are the basic support to build history. The sources are classified as:

• Primary sources. They are those that have been developed practically at the same time as the events we want to know. They come to us without being transformed by any person; that is, as they were done at the time, without being subject to any subsequent modification.

• Secondary sources. They are also called historiographic. They are those that are made from primary sources: books, articles, etc.

answer: the time zones used to be whatever the local authority wanted them to be. one town might have 6am whenever the sun came up and another town had 6am 10 minutes later.  

the trains had a hard time when their orders said to be at a certain point at 6am.  

6am, but who's 6am.  

the railroads got together and set the time zones more or less along the longitude lines across the country.

explanation: