i am not sure but here is my best guess
Answer:
las clases difíciles
Explanation:
Add an <em>-s</em> to <em>clase</em>, and add an <em>-es</em> to <em>difícil</em> because adjectives have to match the plurality of the word they describe.
Answer:
8 is B
9 is B
10 is c
11 is A
12 is A
13 is B
14 is C
15 is A
Those are what I think the answer is
