请帮我把下面着段英语中的词组,结构,语法给找出来!
he was a math teacher three years ago.he taugt well and his student liked him.So he decided to work in the high school all his life.But a terrible acident changed his fortune.one spring he brought his class to visit a place of interest.The children saw a lto of interesting thing and had a good time there.But on thier way back to school,thier bus was hit by a trunk beacuase the yong driver was drunk.Five student died and more than half of the chldren were hurt in the accident.He didnt know how it bad happened and was very afraid it.After he came out of the hospital,he left his school and bacamea policeman.he triedhis best to stop the driver from violating the regulations.