He laboured at a task.
他努力做一件工作。
The first steam locomotive, introduced in1825, had a top speed of only thirteen mph, and the great sailing ships of the time laboured a long at less than half that speed.
1825年推出的第十辆蒸汽机最大速度每小时仅为13英里，而那时的大帆船行驶得更慢，还不到这个速度的一半。
The old man laboured up the hillside.
老人吃力地登山.
