Once upon a time a poor farmer taking a sack of wheat to the mill did not know __1__ to do when it slipped from his horse and fell __2__ the road. The sack was __3__ heavy for him to lift, and his only hope was that presently some one would come riding by and lend a hand. 第一空答案是：（单选）—5分
A another
B what
C too
D onto
E before