1. Is this ...`s book (ruler / pencil case)?- Yes, it is./ No, it isn`t. 2. Whose ... is...

Question

1. Is this ...`s book (ruler / pencil case)?- Yes, it is./ No, it isn`t.
2. Whose ... is this? - It`s ... .
3. What colour is your ...? - It`s ... .

Answer 1

1 ruler
2 book,   ruler's
3 book,      green