Choose the best answer to complete the following sentences.
16. That _______ ears are huge!
B: elephants'
A: elephant's
17. In the forest _____ all the branches were waving in the wind.
A: tree's
B: trees
18. The teacher looked at all the _______ work and chose the best artist.
A: student's
B. students
19. Where have I seen that ______ face before?
A: girl's
B: girls
20. All the ________ uniforms got dirty at that game
B: boys
A boy's