Is the backpack on the desk?    _____________.

-- Are these pens ?  ---Yes, ______.

_____your friend come from England? Yes, he’s an English boy.

—Must we keep the window open all the time? 
A. No, you mustn’t  B. No, you can’t.   C. No, you don’t have to.

—Does she ______ a knife?
—No, she _________.

-Did you go to Jack’s birthday party?
-No, I ____

--                 they like oranges?
---No,they             .

—Is that Helen’s aunt?
---                  .That is Mary’s aunt.

----Is this Grace?
----_________.
A. Yes, she is.   B. Yes, it is.  C. Yes, this is.

----Is Liu Fang your aunt?
----________.
A. No, it isn’t.      B. No, she isn’t.   C. Yes, it is.