试题题干
Tones are pitch variations that refer to morphologically defined segments to the extent that different（ ）in a language are distinctive. Pitch variations can distinguish meaning just like phonemes.
参考答案
正确答案：
试题解析
本题主要考查声调。声调是某种程度上讲从形态定义的音高变化，一种语言中不同的音高是有区别的。音高pitch的变化就像音素一样能区分意思。答案为C