不失真测试条件中,要求幅频特性为( ),而相频特性为( )。
A. 线性
B. 常数
C. 是频率的函数
D. 没有要求
Fill in a suitable adjective or adverb in its appropriate form in each blank.Rainy days are cold, but we have the _________ weather of all on clear, windy days in winter.
The Rocky Mountains are high, the Andes are higher yet, and the Himalayas are the ______ in the world.
He always talks seriously, but his wife often talks even _____________.