Our teacher asked us to write a letter in English this morning. Aninety-wordB．ninety-wor

问题补充：

Our teacher asked us to write a letter in English this morning.

A．ninety-word

B．ninety-words

C．ninety word

D．ninety words

答案：

解析：修饰名词表示量，可用连字符将它们连在一起，不可以使用复数，故本题选A。