In the front of the classroom _________．

1. A.
   is the desk for the teacher
2. B.
   has the desk of the teacher
3. C.
   it is a desk for the teacher
4. D.
   has it a desk of the teacher

In the front of our house stands a tall tree with many green leaves.

             A                B               C         D

In the front of the lecture hall ________ a professor.

1. A.
   sits
2. B.
   sitting
3. C.
   to sit
4. D.
   was sat

In the front of the lecture hall ________ a professor.

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