【正确答案】The description of English vowels needs to fulfill four basic requirements:
1)the height of tongue raising(high, mid, low)
2)the position of the highest part of the tongue(front, central, back)
3)the length or tenseness of the vowel(tense vs. lax or long vs. short)
4)lip-rounding(rounded vs. unrounded)
For example, we can describe the English vowels in the following way:
high front tense unrounded vowel
[u] high back lax rounded vowel
mid central lax unrounded vowel

【答案解析】[解析] 考查元音的语音描述，属识记范畴。元音的描述要满足四项基本要求，只要把该四项要求答出，即可得满分。