A method of precise levelling under unequal back-and fore-sight length is studied and presented in this paper.

本文研究提出了在前后视距不相等的情况下进行精密水准测量的方法，分析了具体的实测方案。

youdao

There certainly were tears in his when, at length, having watched the train out of sight, he turned round.

而最终当他目送列车驶出视线，转过身时，他眼里也噙满了泪。

youdao

The boat that now arrived, assured by the answering signal that all was well, soon came in sight, white and silent as a phantom, and cast anchor within a cable's length of shore.

那艘帆船还是等在外面，在观察回答的信号究竟对不对，不久，它就静悄悄地驶近了，只见白朦朦的一片，象是一个幽灵似的，在离岸一箭路以外抛了锚。

youdao