boarding line

例句：

1. 1.The boarding line is always crowded with people waiting to board the plane.
   登机口总是挤满了等待登机的乘客。
2. 2. We need to check in at the boarding line before we board the train.
   我们需要在登车前在检票口进行安检。
3. 3.The flight attendants were busy directing passengers to their boarding lines.
   空乘人员正在忙碌地指导乘客前往他们的登机口。