Usually low key is used for emphasis and contrast; mid key indicates an expected, neutral attitude; and low key provides low information.（）

Pitch is produced by frequency of vibration of the voca...

判断题Pitch is produced by frequency of vibration of the vocal cords. The higher the frequency, the higher the pitch.（）

Of the two types of sentence stress, sense stress shows...

判断题Of the two types of sentence stress, sense stress shows contrast, while logical stress shows meaning.（）

The back-chaining technique means the students repeat a...

判断题The back-chaining technique means the students repeat a sentence after the teacher, starting from the end part of the sentence and moving towards the beginning.（）