They were walking to the railway station when they met their friends的同义句急改为下面的形式They were going to the railway station when they met their friends
问题描述：
They were walking to the railway station when they met their friends的同义句
急
改为下面的形式
They were going to the railway station when they met their friends
答
They met their friends on their way to the railway station
答
on foot