Here are the sentences with the correct prepositions:

1. It's my holiday next week. I'm going **to** Spain.
2. There was a big crowd **in** the shop waiting for it to open.
3. That man is an idiot. He pushed me **into** the swimming pool.
4. I went **to** the chemists just now, but I didn't notice if it was open.
5. David hurt himself. He fell **off** his bike.
6. There's a café **at** the top of the mountain. You can have a coffee there before you go down.
7. The sheep got out **through** a hole in the fence.
8. Pompeii is quite **near** Sorrento. It's only a short train ride.
9. There's such a crowd. You won't find your friend **among** all these people.
10. Sophie was lying **on** the grass reading a book.
11. He's swimming **in** the river.
12. Where's Julie? She's **at** school.
13. The plant is **on** the table.
14. There is a spider **in** the bath.
15. Please put those apples **into** the bowl.
16. Frank is **on** holiday for three weeks.