Чем можно объяснить разные размеры тел позвонков и расположение отростков?

Во многих предложениях желательно использовать perfect, но исходя из задания:

1. I went to the supermarket.
2. We found everything we wanted.
3. Brian walked to school.
 4. It was a beautiful day yesterday.
5. When Mary and Jake arrived at the party, they looked for Mike but couldn't find him.
6. We saw Star Wars last week. I liked it a lot, but my friends didn't.
7. My TV was broken last week, so I read all my magazines in my free time.
8. Janet made three delicious dishes. We ate all the food.
9. Tony and Tim played basketball as children. 
10. Tim also studied French and piano. 
11. I lost) my wallet yesterday.
12. I found the book that I needed.