Digital switching

digital ['dɪdʒɪtl]

adj. 数字的;数据的;手指的;指状的; n. 手指;（钢琴等的）琴键;数字;

digit手指+ al具有...性质→手指可以数数→ a.数字的,计数的

switching

[计] 交换\\n[经] 转换, 调换, 调头

You never know what you can do till you try.

除非尝试，否则你永远都不知道你有何价值。

Do you have change for a twenty-dollar bill?

你付了一张20美元帐单了吗？

I want to ask you for your advice. When I leave school, I want to be an engineer. For years I have been interested in engineering. I have made tools at home and have written articles for magazines. My father says that engineering is not a suitable subject

我希望得到您的指点。中学毕业后，我希望成为一名工程师。多年来，我一直对这个方面感兴趣。我在家制作各种用具，给杂志写文章。我的父亲说工程学不适合女孩子学。他要我学习地理。可是我对这门学科一点也不感兴趣。我尝试阅读有关这方面的书籍，然而，我感到索然无味。我该?2283