Absence of stress on a syllable, or on a word in some cases, is frequently associated inEnglish withvowel the changes that result from unstressed syllables () .
A . reduction
B . pitch
C . loudness
D . quality
出自:伊犁师范-英语语音

完成拼图验证

按住下方滑块,将拼图拖到缺口处后松开。

拼图背景,将小拼图拖到缺口处
向右拖动滑块