Exercise 1:
1: at
2: in
3: at
4: in
5: on
6: at
7: at
8: on
9: on
10: at
11: in
Exercise 2:
1: What is the length of that road?
2: He left school at the age of 12
3: What's the age of that building?
4: It's a 48-store high building
5: It's an eight-meter long rope