i want to retire by the time i am thirty可以帮我分析一下为何用by the time i am thirty为何不用at 或on 或in

i want to retire by the time i'm thirty.请分析语法结构我不懂为什么不是by the time when i'm thirty.而是by the time i'm thirty. 英语翻译There are many things that I would be proud of If I'd only invented them such as the wheel The washing machine and the tumble dryer On these inventions surely I could retire I want to retire No longer required I want to get by without the i want to retire by the time i am thirty可以帮我分析一下为何用by the time i am thirty为何不用at 或on 或in 帮我检查一下这些题有没有做对 thank you~1.When I _retire_(retire),I want to _live_(live) somewhere by the sea.2.I think I _will go_(go) shopping after I _finished_(finish) work today.3.I _will tell_(tell) you as soon as I _hear_(hear) an I am going to retire somewhere quiet and beautiful.retire somewhere.二者为什么连用? 帮忙改错、1. when i will grow up ,i'm going to do some interesting things. 2. My mom always asks me to do what do i want to do . 3. I'm gong to retire beautiful somewhere. 4. I want to go to beijing by t什么 I want to go to anywhere by myself I just want to by your side forever. I want to stay by your side each day I want to always be by your side 怎么读 I want to do you only,be by your I want to take you by the hand. All I want is to have you by my side. I'm going to move to another place after I retire.(同义句转换)I'm going to move ____ _____ after I retire. In fact,I also want to stand by your side,do not want you to be I always dream( ) after I retire. A.have B. toI always dream( ) after I retire. A.have B. to have C.of having D.to I am going to retire somewhere quiet and beautiful的同义句I am going to retire in some place （ ）（ ）quiet and beautiful急