Definition
from the very beginning to the end of a relationship or process; continuously throughout.
（关系或过程）自始至终、一向。
She was doubtful about this job all along the line.
她对这份工作从一开始就抱有怀疑。
This project had problems all along the line, we should have stopped it earlier.
这个项目从一开始就有问题，我们应该早点停止它。
He has been supportive of the idea all along the line since we started collaborating.
自从我们开始合作以来，他一直都支持这个想法。