Which of the following might be the best title of the passage（）

单项选择题It can be inferred from the passage that while communicating, （）

A．listening is a perfect way to respond to others
B．people keep silent because they don"t know the answer
C．keeping silent means being too shy to speak
D．it is easy to form the habit of listening silently

单项选择题7（）

A．before
B．after
C．first
D．so