The professor walked onto the platform and seated himself in a chair, ____ for answering questions.

A、had prepared B、being prepared   C、preparing    D、prepared

The professor walked onto the platform and seated himself in a chair,________ for answering questions.

A.had prepared             B.being prepared?

C.preparing　               D.prepared?

The professor walked onto the platform and seated himself in a chair, ____ for answering questions.

 A. had prepared     B. being prepared   C. preparing        D. prepared

The professor walked onto the platform and seated himself in a chair, ____ for answering questions.

A、had prepared     B、being prepared C、preparing  D、prepared