Digital Data Network ( DDN ) is a data transmisston network using digital channels.数字数据网 ( DDN ) 是采用数字信道来传输数据信号的数据传输网.Driect line 、 ISDN 、 DDN 、 Frame relay 、 ADSL 、 Broadband 、 Hunting line. 、 E 1、 PRI and so on.如:直线电话、...
Many of us conform to the outdated customs laid down by our forebears.我们许多人都遵循祖先立下的过时习俗。It has been moulded by the thought of a hundred generations of our forebears.它是长久以来我们历代先人的思想塑造出来的.I'll come back to the land of...
A new method for fabricating micro - optical elements with aspherical outlines is discussed.讨论了一种制作非球面微光学元件的新方法.This paper presents the design principle and method of an opticalfor plastic aspherical door scope.介绍了一种塑料非球...
They moved out from the airport at a brisk clip.他们迅速撤离机场。Don't forget to clip the token and stick it on your card.别忘了剪下标志，贴到你的卡上。The BBC World Service Television news showed the same film clip.英国广播公司对外电视频道的新闻节目播放了同样...