国家开放大学 / 综合英语（1）
正确率：100%
What is true about the words?
a. They are used to express feeling only
b. They can't be written down
c. They are spoken or written sounds
d. They are soundless signs
a. They are used to express feeling only
b. They can't be written down
c. They are spoken or written sounds
d. They are soundless signs
参考答案：