I am busy working at my lessons.这里的at是不是用错了啊?为什么?

I am busy working at my lessons.这里的at是不是用错了啊?为什么? Now i am fine and busy---my lessons.A.at B .about C.and D.wi I am busy （）my lessons a.at b.about c.and d .with说明理由 I am now busy preparing for my lessons为什么把for去掉啊 i am quite busy at be busy at do吗 为什么课本上是I am busy at work every day. I am at my my father is at work.这里at 为什么他同义于working 首字母填空1. I was h__________, so I am good at my lessons I love all my lessons at school. I am busy with my lessons while my mother is busy cooking___ I can't help___housework at home because I am busy with my h