My hero is a doctor,who save my life when I could have died.In fact,she has saved quite a fewchildren's lives.At the age of five,I was serious ill and my life was in danger.Myparents were all worried if I could recover from the disease,I was lucky enough to meet Dr.Jack,a great doctor who is always east to talk.He did lots of different tests to find the medicine to cure me.I owe to him that I am still alive.Dr.Jack,he has made a big difference to the

My hero is a doctor,who save(改为saved) my life when I could have died.
In fact,she(改为he,根据下文,此医生是男滴.) has saved quite a few children's lives.
At the age of five,I was serious(改为seriously) ill and my life was in danger.
My parents were all(改为both,指“两者都”.all指“三者或三者以上都”) worried if I could recover from the disease.
I was lucky enough to meet Dr.Jack,a great doctor,who is always east to talk.
He did lots of different tests to find (加上out,表示“找出”.为了找出救我的药,做了各种测试.find强调结果,指已经发现了的.) the medicine to cure me.
I owe to him that I am still alive.
Dr.Jack,he(改为who) has made a big difference to the lives of others,is respected by many people in our city.