【简答题】Listen again and complete the following conversation with what you hear. You're the next to __________. Are you ready? I know, but now I can't __________ and my mouth feels dry. Why don't you believe ...
【单选题】在某放大电路存在频率失真但无非线性失真情况下,当输入为正弦信号时,输出信号 ____(a 、仍为正弦,并且与输入同频率, b 、仍为正弦,但频率与输入不同, c 、为非正弦);当输入为方波信号时,输出信号 ____(a 、仍为方波,并且周期与输入相同, b 、仍为方波,但周期与输入不同, c 、波形发生失真)。