大写和小写字母都被认为是不同的。

Uppercase and lowercase letters are to be considered distinct.

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暗示：使用大写字母和小写字母，数字，符号，如！

Hint: Use upper and lower case characters, Numbers and symbols like!

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书面沟通：擅长画竖线，即大写字母“I”和小写字母“L”。

Written Communication: good at drawing vertical lines which are Upper case "I" and lower case "L".

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Now, once you know each of those, you can now do 25 more upper case letters and 25 more lower case letters then there are some other stuff like punctuation and things you see on the keyboard.

一旦你知道两者中的任何一个，你就知道了另外25个,大写字母和小写字母,标点和在键盘上的,各种符号也有ASCII码。

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