1. It’s a very good room. It is the best room in the hotel. The superlative form "best" is used to compare the room with all the other rooms in the hotel. By using the preposition "in," we are indicating that the room is the best among all the rooms in the hotel. 2. It’s a very cheap restaurant. It’s the cheapest in town. The superlative form "cheapest" is used to compare the restaurant with all the other restaurants in the town. By using the preposition "in," we are indicating that the restaurant is the cheapest among all the restaurants in the town. 3. It’s a very happy day. It was the happiest day of my life. The superlative form "happiest" is used to compare the day with all the other days of my life. By using the preposition "of," we are indicating that the day was the happiest among all the days of my life. 4. She’s a very intelligent student. She is the most intelligent in the class. The superlative form "most intelligent" is used to compare the student with all the other students in the class. By using the preposition "in," we are indicating that the student is the most intelligent among all the students in the class. 5. It’s a very valuable painting. It is the most valuable in the gallery. The superlative form "most valuable" is used to compare the painting with all the other paintings in the gallery. By using the preposition "in," we are indicating that the painting is the most valuable among all the paintings in the gallery. 6. Spring is a very busy time for me. It is the busiest time of the year. The superlative form "busiest" is used to compare spring with all the other times of the year. By using the preposition "of," we are indicating that spring is the busiest time among all the times of the year. 7. He’s a very rich man. He is the richest man in the world. The superlative form "richest" is used to compare the man with all the other men in the world. By using the preposition "in," we are indicating that the man is the richest among all the men in the world. 8. It’s a very big castle. It is the biggest in Britain. The superlative form "biggest" is used to compare the castle with all the other castles in Britain. By using the preposition "in," we are indicating that the castle is the biggest among all the castles in Britain. 9. It was a very bad experience. It was the worst experience of my life. The superlative form "worst" is used to compare the experience with all the other experiences of my life. By using the preposition "of," we are indicating that the experience was the worst among all the experiences of my life. 10. He’s a very dangerous criminal. He is the most dangerous in the country. The superlative form "most dangerous" is used to compare the criminal with all the other criminals in the country. By using the preposition "in," we are indicating that the criminal is the most dangerous among all the criminals in the country.