Classification of vowels is made up of the following EXCEPT（　　）。

单项选择题

A、the openness of the mouth

B、the position of the tongue

C、the shape of the tip

D、the width of the vowels

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　　答案：D

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　　[华图教育答案解析]：英语元音有四种分类：the position ot’the tongue in the mouth；the openness of the mouth；the shape of the lip；the length of the vowels。