-Are these your rulers?

-________.

1. A.
   Yes, they're
2. B.
   Yes, they aren't
3. C.
   No, they're
4. D.
   No, they aren't

---Are those his rulers?

---No, ________．

1. A.
   it isn't
2. B.
   they aren't
3. C.
   these aren't
4. D.
   those aren't

---Are those your rulers?

---No, ________.

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