Which of the following is the best definition for secondary source?
o
a. a timeline describing the major parts of an event
o
b. a description of an event written long after it took place
o
c. a diary entry written by a person who witnessed an event
o. d. a photograph taken at an event by a trained historian

B. A description of an event written long after it took place.

Explanation:

A primary source is something that comes from the time being researched, so a secondary source is something that comes from after that point.

it foreshadows the theme of the paragraph and hints the topic that will be discussed in the paragraph!

explanation:

the addition to geographic boundaries that might have  kept the people of the huang river civilization from traveling to far distance region is that they had learned about the other river valley civilizations but feared contact would bring invasion.

hope this .

plz give me brainliest!