On seeing Mrs.Richards( )towards him , he fled .
A. to walk B. having walked C. walk D. walked
On seeing Mrs.Richards( )towards him , he fled .
A. to walk B. having walked C. walk D. walked
C walk
是see sb. do的形式哈,因为前面已经用了seeing.
如果选项需要强调walk的过程,也是可以用ing形式的。
C
see sb. do sth.看见某人做某事
他一看见理查德夫人向他走来,他马上逃走了。