Notice that the noun form does not use a hyphen.

请注意这种名词形式不加连字符。

Always check your dictionary if you are unsure if a compound noun requires a hyphen.

如果你不确定复合名词是否需要连字符，一定要查字典。

No, hang on. Okay, one word, a letter and a number and... maybe a hyphen. 3D printer.

不，让我想想。好吧，一个词、一个字母、一个数字、以及一个连字号吧3D打印机。

If you have used bullets, replace them with hyphens.

如果你用了项目符号，把它们换成连字符。

Notice that both 15-foot and 10-foot come before the noun and there is a hyphen between the words.

请注意" 有15英尺高的" 和" 有10英尺高的" 都放在名词前，并且单词之间有连字符。

You can say a three-week trip and here you don't need an s but you need a hyphen.

你可以说“三周的旅行”，这里你不需要加 s，但是你需要加连字符。

Even though these are two different words, the hyphen makes it one word.

即使它们是两个不同的词，连字符使之成为一个单词。

'Ultra' is added to adjectives, using a hyphen but not always.

ultra 被加在形容词上，会使用连字符，但并不一定总是这样。

So a word like open-minded is joined together by a hyphen.

所以像 open-minded 这个用连字符连接的词。

A hyphen is required for compound nouns made from two nouns.

由两个名词组成的复合名词需要连字符。