问题：
—Where is our English teacher?
—She is in the classroom, _____ the exercises _________ the students have done at home.
A．explaining; /
B．explaining; for
C．explained; to
D．explained; from
—Where is our English teacher?
—She is in the classroom, _____ the exercises _________ the students have done at home.
—She is in the classroom, _____ the exercises _________ the students have done at home.
| A．explaining; / | B．explaining; for |
| C．explained; to | D．explained; from |
参考答案：