2/ 1. heavier, the heaviest
2. more comfortable, the most comfortable
3. deeper, the deepest
4. more interesting, the most interesting
5. more difficult, the most difficult
3/ 1. Can
2. May
3. Must
4. Can
5. Must
4/ 1. liked
2. was work
3. looked, washed, shaved, combed
4. got, did, had, went