The bus hit the huge stone by the road heavily _________ he could stop it.

A. after                B. before           C since             D. until

The bus hit the huge stone by the road heavily ________he could stop it.

A. after             B. before                  C. since                  D. until

The bus hit the huge stone by the road heavily _________ he could stop it.
A. after                B. before           C since             D. until

The bus hit the huge stone by the road heavily ________ he could stop it．

1. A.
   after
2. B.
   before
3. C.
   since
4. D.
   until