Well, your question is "How" do you answer the question, so I won't give you the answers (because I have no clue anyways)
Your simply answer 7-15 by filling in the missing word in the box. The sentences are missing words, and you have to find the correct form of that word that fits the sentence and makes it complete. In spanish, of course.
~Hope this helps!
An experiment trying to decide what kind of soil do plants like more
What does Gaston and Lucia decide to do? follow the recommendation of WHO? Why gastón and lucía want to get tickets for students? How and when can they get tickets for students? What happens when they arrive at the school office? What do they ask the secretary? Do you think they get the tickets?