1
an old book
2
a window
3
a horse
4
an airport
5
a new airport
6
an organization
7
a university (!)
8
an hour (!)
9
an economic problem
1
an old book
2
a window
3
a horse
4
an airport
5
a new airport
6
an organization
7
a university (!)
8
an hour (!)
9
an economic problem