In order to prevent the fire spreading, some of the houses nearby had been ________ before firemen arrived．

1. A.
   burned down
2. B.
   pulled down
3. C.
   put down
4. D.
   turned down

In order to prevent the fire spreading, some of the houses nearby had been ________ before firemen arrived.

   A. burned down    B. pulled down      C. put down        D. turned down

 In order to prevent the fire spreading, some of the houses nearby had been ________ before firemen arrived.

   A. burned down    B. pulled down      C. put down        D. turned down

In order to prevent the fire spreading, some of the houses nearby

_____before the firemen arrived.

A. have been pulled down         B. have pulled down

C. had been pulled down          D. had pulled down

.In order to prevent the fire spreading, some of the houses nearby _____before the firemen arrived.

  A. have been pulled down        B. have pulled down

  C. had been pulled down        D. had pulled down