1.表时间：
意为：到.时候为止
We’ll have finished the work by ten o’clock.
2.表交通方式：
意为：乘坐某种交通工具
He came here by sea/ plane/bus.
3.表方位：
在.附近
We often go out for a walk by the river.
4.表方式
用某种抽象的方式
You can learn English well by doing more listening,reading.
5.觉得有用就给个最佳,欢迎来问.