2刃铣刀作用:一个英语问题：是They are helpful for me还是They are helpful to me

一个英语问题：是They are helpful for me还是They are helpful to me 一个英语问题：是They are helpful for me还是They are helpful to me they are onto me是啥意思？ where are they running ?和where are they walking?中文的表达是? here it is 和here they are 的问题!! They are from China What are they doing? They are haveing Maths. Leaving things as they are They are some old citied They are flying ? the mountain.