问题
It is a pity that none of the ______ stopped ______ the poor man lying there, begging.
A:passer-bys; to help
B:passers-by; helping
C:passer-bys; helping
D:passers-by; to help;
B:passers-by; helping
C:passer-bys; helping
D:passers-by; to help;
正确答案是：
