The answers are simple. These sentences are a few different types, but for example, I'll do 6.
The correct answer for number 6 is: We didn't have much time, so we didn't read the final chapter, but we still enjoyed the book.
You have to turn these sentences into compound-complex sentences, which means that you turn them into a single sentence with one independent clause and two dependent clauses. The property of turning them into a single sentence remains the same for all your questions on compound complex sentences. I would also suggest to look up conjunctions if you don't already know what they are, since they'll be crucial for the re-writing as compound-complex.