devoted all his life to studying math when he was young为什么是s

He used to be devoted to his teaching when he was young; He devoted all his life to work hard in people`s interests. He devoted all his life to help the poor. Qian Xuesen devoted all his life to ________________ China’s He has devoted all his life to education.He has devoted hims When he was young,Mandela decided to f__for freedom all his He used to () his teaching when he was young; he devoted his life to helping the disabled he devoted his life to the promotion of world peace Devoted his whole life time to science,he finally succeeded 英语翻译he was a devoted son to his mother,who died after much s he has devotes his life to.和he devoted his life to.有什么区别吗