填入适当的关系代词(that, which, who,whom,whose)或关系副词(when.why,where)完成下列句子。 1. The boys________ are playing football are from Class One. 2. Those ______ want to go to the museum must be at the school gate at 7 tomorrow. 3. Mr Liu is the person ________ you talked about on the bus. 4. The professor ________ you are waiting for has come. 5. Football is a game _______is liked by most boys. 6. He likes to read books ________ are written by foreign writers. 7. This is the pen _______ he bought yesterday. 8. We’ll go to hear the famous singer _______ we have often talked. 9. Where is the man _________ I saw this morning? 10. The season_________ comes after spring is summer. 11. I visited a scientist ________ name is known all over the country. 12. He has a friend ______ father is a doctor. 13. I once lived in the house _____ roof has fallen in. 14. I still remember the day _____ I first came to this school. 15. The time _______ we got together finally arrived. 16. Shanghai is the city ______ I was born. 17. The house ______ I lived ten years ago has been pulled down. 18. Please tell me the reason ______ you missed the plane. 19. The reason ____ he was punished is unknown to us. 20. All the people ______are present burst into tear