___________ It's his,I thinkA.Whose ruler is this B.Where's his ruler?

___________ It's his,I thinkA.Whose ruler is this B.Where's his ruler?
___________ It's his,I think
A.Whose ruler is this
B.Where's his ruler?

___________ It's his,I thinkA.Whose ruler is this B.Where's his ruler?
A.Whose ruler is this
回答是谁的,问句对应也应该是谁的

A。
回答说的是：我想是他的。
提问当然用疑问词whose：谁的