work hard at\on\for\to什么地方不同?

work hard at\on\for\to什么地方不同? work hard on和work hard at 是work hard at sth.还是work hard on sth. work hard at和work hard on 的区别 英语翻译He kept on trying and was rewarded for his hard work.At It's hard( )us( )the work on time.A.for,to finish B.for,fini work hard at hard we are going to work hard ____that day (空中填at还是on或in) every day they work hard( )morning( )evening（at,on,from,to,w .___ is our duty for us young adults to work hard at our les To work hard at our lessons is possible for us改为同义句 To work hard tomorrow for me and obediently more us.On fuel!