1.This is the company which i have ever worked for/at.
或者This is the company where i have ever worked.
2. I will never forget the first day when I went to school.
或者I willnever foget the day when i went to school firstly.(注意,GO TO SCHOOL 是去上学,go to the shcool是去学校）
3.Do you know the girl who is writing now.
4. He has adopted a child whose parents were dead.
5.She has 2 sons , both of whom have graduated from Beijing University.
或者 She has 2 sons who have both graduated from Beijing/Peking University.
(要解释吗?)