伴音信号发送前采用预加重措施，接收端则采取（），以恢复原来伴音中（）与（）频分量振幅的比例。

短语填空。

     I haven't (1)_______ (收到……来信) you for a (2)_______ (两周). I (3)_______ (渴望) your letter.

These days I am very busy. I am trying to (4)_______ (适应) these conditions. However, one thing is

(5)_______ (肯定的). My students (6)_______ (没有概念) of doing experiments. (7)_______ (前几天),

I showed them the weekly chemistry experiment, who had never (8)_______ (遇到) anything like this

before. So they fled. (9)_______ (说实话), I doubt whether I am (10)_______ (改变,有影响) to these

boys' lives at all.