英语问题 thank you for help!

原因状语从句变为分词短语：
eg.Because I felt surprisingly better,I smiled at her and agreed.如果前后主语是同一个人,则分词短语不需要主语,前后时间几乎同时发生,或从句动作先发生,主句动作立刻发生,这是就可变为分词一般式：Feeling surprising better,I smiled at her.
如果前后主语不一致,则可变为独立主格.如：
Because my mother was ill,I had to look after her at home.前半句原因状语变为分词就是My mother being ill,I had to look after her at home.前半句原因状语中保留主语my mother,动词was 变为being.再比如
eg.A young man in Teheran was tired of sleeping on the floor,so he saved up for years to buy a real bed.这是一个用so连接的并列句,但前半句可转变为作原因状语的分词短语即：Being tired of sleeping on the floor,a young man in Teheran saved up for years to buy a real bed.在这句话中,tired是一个过去分词转变的形容词,这是前面的being就可以省略即：Tired of sleeping on the floor,a young man in Teheran saved up for years to buy a real bed.
如果分句所表示的动作发生在位于动词所表示的动作之前,或动作已经完成或结束,并侧重去说明动作,则可以把分句变为分词的完成时如：Because he had lived in Guangzhou for quite a long time,he knew the city well.前半句用了完成时,这时就可变为Having lived in Guangzhou for quite a long time,he knew the city well.
当然定语从句也是可以变为分词短语的,如：
The teacher who is singing a folk song on the stage teaches us English.这句话中的定语从句：who is sing a folk song on the stage可以变为现在分词短语singing a folk song on the stage 因为定语从句动作在说话的时候还在进行.再比如：
It is actually a small swiss aeroplane which is called a Pilatus Porter.这句话中的定语从句：which is called a Pilatus Porter可以变为过去分词短语：called a Pilatus Porter