—What class are they having?
—Math. Their math teacher is _____ the classroom.

—What class are they having?

—Math. Their math teacher is _____ the classroom.

A．in the front of      B．in front of         C．on               D．behind

—What class are they having?
—Math. Their math teacher is _____ the classroom.

1. A.
   in the front of
2. B.
   in front of
3. C.
   on
4. D.
   behind

-What class are they in? Do you know? 

-No, we ________ .

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