Answer:
A:death
Death is a fearful thing to some people.
16. doesn’t grow
17. Has played
18. Has stopped
19. Will you play
20. Usually grow, haven’t grown
21. Has to
22. Must
23. Have to
24. Musn’t
25. Had to
26. Have to
27. Must
NO! When you use the word I it reprresents an opinion, a persuausive essay is nothing but facts.
The answer is D.
"Keep", "factor", and "calculate" are all verbs in the list of things the new system allows teachers to do. The other sentences are inconsistent with their list of verbs/adjectives/nouns. Thus, option D is the only one that is grammatically correct.
I am not too good at explaining, so let me know if you are still confused.
Hope this helps! :)