Нужна помощь в упражнении

Complete the sentences with the correct form of the words in brackets.

1. His record is (practical) of all.
2. This exercise is (big) than the last one.
3. The East-Siberian Institute of the MIA of Russia is considered one of the (large) law enforcement schools.
4. English is (difficult) subject that I study.
5. She is (good) investigator in our division.