Mary____ a math problem with her classmates when the math teacher knocked at the classroom door.( )
A. |
has discussed |
B. |
was discussed |
C. |
was discussing |
D. |
discusses |
Mary____ a math problem with her classmates when the math teacher knocked at the classroom door.( )
A. |
has discussed |
B. |
was discussed |
C. |
was discussing |
D. |
discusses |