First Marconi sent the Morse code letter s a distance of 300 feet.

马可尼首先将摩尔斯码的字母s发送了300英尺远。

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Phonics provides children with a code: pupils learn individual letter sounds and then learn how letters work in groups.

拼读法为孩子们提供了一套规则：学生们学习单个字母的发音，然后学习这些字母组合在一起时如何发音。

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The small xx represents the local language, which is a two letter ISO-639 language code and the capital XX represents the local country, which is a two letter ISO-3166 country code.

小写的xx 表示本地语言，它是一个 ISO-639 语言编代码，为两个字母；大写的 XX 表示本地国家，它是一个 ISO-3166 国家代码，为两个字母。

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Because what you don't see in this file is any code a that actually says put a letter of the alphabet at the top left hand corner of the screen and then put the next character to the right in other words, I'm taking for granted at this moment in time that my computer knows how to print something to the screen.

就是这些你在本文件中看不到的一些代码,实现了将首字母,放在屏幕的左上角,然后把其他字母加在其右边，我想当然地认为,我的电脑知道如何打印相应信息到屏幕上。

哈佛公开课 - 计算机科学课程节选

The culprit was apparently a mix-up between the similarly pronounced cities and the three-letter code used by airlines to distinguish airports.

CNN: Travel nightmare: couple flown to wrong continent

Unlike in the Volker case, she examines the entire 6 billion-letter DNA code.

FORBES: Sequencing A Child's DNA -- And Convincing An Insurance Company To Pay

The three-letter airport code on the tickets issued to the couple by the airline read DAC, the code for the airport in Dhaka.

CNN: Travel nightmare: couple flown to wrong continent