making questions by using " Whose "

I am teaching 5th unit,"Whose cap is this?" .
Since we went through lots of activities, kids were used to "Whose .....? " , "It's mine/ ours ...." ,
I wanted to try another ways to use "Whose...? " , more than simple like "Whose cap is this?", (because of the effect of Critical pedagogy class? I don't know.. haha...)

Today, I let them to make questions by using
"Whose" , that everyone think that it is ours, but that we usually don't think deeply,
First , I gave them a question , "Whose Dokdo is this ? " , Koreans usually says "It's ours" , Japanese says "It's ours"

They think these questions ...
"Whose nature is this ? "
"Whose east sea is this ? "
"Whose Bal hae ( which is controversial issue between Korea & China ) is this ? "
" Whose 직지심체요절 (the book, which is the pressed by metal type for the first time in Korea but France has it, now ) is this ? "
"Whose school is this ? "
one student said " Whose air is this ? "
....
At last , arising memorial day in this month, thinking about the ownership of our country.

They are brilliant than I think !