According to the shape of the lips, vowels can be classified into close vowels, semi-close vowels, semi-open vowels and open vowels. A: 正确 B: 错误

中国大学MOOC: In the following vowels, are back vowels.

中国大学MOOC:"In the following groups of vowels, are mid vowels.";

中国大学MOOC:" In the following groups of vowels, are not all front vowels.";

中国大学MOOC: Pure vowels can be classified into three categories: front vowels, central vowels and back vowels. The two vowels/ɜː/ and /ə/ are classified into ______ vowels because they are made with the middle part of the tongue being raised.

In the following groups of vowels, are not all front vowels. A: /ɜ:/, /ɪ/, /e/ B: /ɪ/, /ʌ/, /ʊ/ C: /u:/, /i:/ /ɜ:/ D: /e/, /æ/, /ʌ/

What criterion is NOT used to classify the English vowels(). A: The openness of the mouth. B: The shape of the lip. C: The length of the vowels. D: The position of the teeth.

/ʃ/, /j/, /w/ are semi vowels.( )

中国大学MOOC: How can you distinguish between front vowels, central vowels, and back vowels?

The sound segments are grouped into consonants and vowels.（）