A reader can tell that the meaning of “obnoxious”

see below

Explanation:

ending( suffix) -ous is commonly used for adjectives,  the adjective that describe someone's personality

i do not know what the passage is but i can give some examples

1. repetitive phrases may be used to create a emphasizing tone

2. pauses in sentences are used to create a dramatic effect but can also be suspenseful

3. using lots of exclamation marks and loud speech such as words in all caps can be creating a excited or possibly angry tone.

4. using lots of questioning phrases my mean that they are in suspicion of something.

5. using lots of questionable statements or questions can imply of a sneeky or sly tone.