幅度调制
参考答案：
就是用基带信号去控制高频正弦载波的振幅，使其随基带信号的规律作线性变化。载波的频率和相伴保持不变。
You must try some of her home-made wine and it’s quite ____ experience! I know from ____ experience it is very good.
A．the; the
B．an; an
C．an; /
D．/;an
可缩短动作电位时程的抗心律失常药是：
A．胺碘酮B．腺苷C．多非利特D．普罗帕酮E．普萘洛尔
