The correct answers are: (8) anything and (9) anyone.
Explanation
- In negative questions like “Why haven’t I heard … from you?” we use anything rather than something: “Why haven’t I heard anything from you?”
- For “Are you seeing … these days?” (meaning dating), the natural word is anyone: “Are you seeing anyone these days?”
Alternative natural options: (8) a word (“Why haven’t I heard a word from you?”) and (9) someone (less common in questions: “Are you seeing someone these days?”).