What is a diphthong?
What is a diphthong?
The first vowel of a diphthong is as long as the second vowel.
The first vowel of a diphthong is as long as the second vowel.
Which word with the diphthong(双元音) is different?
Which word with the diphthong(双元音) is different?
Which is NOT a rising diphthong?（ ） A: ei B: ai C: au D: a:
Which is NOT a rising diphthong?（ ） A: ei B: ai C: au D: a:
1