Im pretty sure that you add S example
la : las
It's comunicas because the question is in the tu form.
You don't serve your family, or know them (because you already do).
Answer:
1. por
2. por
3. para
4. por
5.para
6. por
7. por
Explanation:
This one is pretty easy since it makes most since to use "por" on most of them
