4. which one of the following statements about a topic sentence and a main idea is accurate? a. a topic sentence and a main idea are always the same thing. b. a topic sentence is the central idea of a paragraph, while a main idea is the central idea of an entire text. c. a topic sentence is found in the introduction, while a main idea is found in the conclusion. d. a topic sentence does not change position, but the main idea can be found in multiple places.

How does this excerpt develop the central idea that espionage during the civil war was often carried out by untrained citizens? it enhances the reader’s understanding by explaining why training was unnecessary. it changes the reader’s perception of what information a spy was able to obtain. it explains an ordinary person’s motivation for conducting espionage against the enemy. it adds moral complexity to espionage, due to the use of secret and dangerous methods.