Choose the correct preposition. 1 the house is in/at the shape of a seashell. 2 there are posters on/in the walls. 3 you can't walk in/at space. 4 there are small huts in/on the island. 5 the flat is at/on the third floor. 6 we're excited for/about our new house. 7 the place is popular with/for tourists. 8 the island is home for/to twenty families.