Используйте нужную степень сравнения:
1) In december the days are the (short)
2) This girl is (clever) in our class.
3) Pam is (fast) than her boy-friend.
4) These compositions are (good) than those ones.

1) In december the days are the shortest 2) This girl is the cleverest in our class. 3) Pam is faster than her boy-friend. 4) These compositions are better than those ones.