Assuming you meant explanatory text and not exclamation text, the answer would be brackets. For example, say your quotation is "She wrote the book." If you are quoting this directly in a paper, you want your audience to know who "she" is. So, you use brackets, and write the following: "[J.K. Rowling] wrote the book." Hope this helps.
Answer:
The secret agents, disguised in civilian clothes, managed to easily <u>blend</u><u> </u>in with the crowd and get downtown
Is there anyway to emphasize that question you're asking?
Because it was too loud or because it didn’t have space
It would be imagery because the excerpt is very descriptive.