by yourself

漢語翻譯

例句：

1. How long were you by yourself in the classroom?
   你獨自一人在教室里多長時間了?
2. Are you sure you did this exercise by yourself?
   這個練習真是你自己做的嗎?
3. Since you are already of age now, you should solve the problems by yourself.
   你已經成年了，這些問題要自己解決。
4. You can't go mountain climbing by yourself.
   你不能自己去登山。
5. I believe that you can work out this problem by yourself.
   我相信你自己能做出這道題的。