How long before did he join the army?改错.

How long before did he join the army?改错. How long before did he join the army?改错 manage用法-Did he manage to join the army?-He_____,but he_____ 有关状语从句It will be 4 years before he can join the army.为什么只能用b He join the army when he was fifteen(保持原句意思）He join the army It is ten years since he ____(join) the army how long did his family live in new york before he was five How long did the performance( ____ they read the book before?参考答案填Have,那么填How long did 为什么 by the way,how long did you live with your bf before? How long have you____the army before join the army everyone has to have a m____ exam