Hey there!
Here are your answer:
8. ans:- Have you finished writing?
☆ Explanation: Since,the above sentence gives a sense of asking something, that why I've put a question mark in the end of it.
9. ans:- She said, "I'm sorry."
☆ Explanation: Since, in the above sentence the reporter is reporting something about a third person, and it is in active voice. We,know that in "Voice", in case of active voice quotation are used so that why I've putt two quotation marks.
10. ans:- Apples,mangoes,bananas are my favourite.
☆ Explanation: In the above sentence, it is said about some fruits. And when we say about so many things in one sentence we use comma to separate them. That's what I did.
Hope it helps