the children are going to school on foot.对划线部分提问

问题描述:

the children are going to school on foot.对划线部分提问

没有线呢?
如果对children划线,就是who are going to school on foot?
如果对school划线,就是where are the children going to on foot?
如果对on foot划线,就是how are the children going to school?