The students _______ busily when Miss Brown went to get a book she _______ in the office.　

A. had written, left　        B. were writing, has left

C. had written, had left　      D. were writing, had left

The students _______ busily when Miss Brown went to get a book she _______ in the office.　

A. had written, left　    B. were writing, has left C. had written, had left　     D. were writing, had left

The students ________ busily when Miss Brown went to get a book she ______ in the office.

A．had written, left　　　　　B．were writing, has left

C．had written, had left　　　D．were writing, had left

The students _______ busily when Miss Brown went to get a book she _______ in the office.　

A. had written, left　         B. were writing, has left

C. had written, had left　  D. were writing, had left

The students ___ busily when Miss Brown went to get a book she ___ in the office.

A. had written ; left              B.were writing ;has left

C.had written ;had left           D.were writing ;had left

The students _____ busily when Miss Brown went to get a book she ____ in the office．

       A．had written; left                                  B．were writing; has left 

       C．had written; had left                D．were writing; had left

 The students _______ busily when Miss Brown went to get a book she _______ in the office.

A. had written; left      B. were writing; has left 

C. had written; had left   D. were writing; had left

The students _______ busily when Miss Brown went to get a book she _______ in the office.　

A. had written, left　　　　 B. were writing, has left

C. had written, had left　　 D. were writing, had left