选择题：周期信号的周期越大，则其频谱的频率间隔（）1 越小2 越大3 不变4 变化不一定

Nancy.s father ________her that he would stop drinking.A. promised B. said

有机体学会对条件刺激和与条件刺激相类似的刺激作出不同的行为反应，巴甫洛夫称其为（ ）。A、刺激泛化 B、刺激比较 C、刺激分化 D、行为强化

14.Although there were only 4 horses ________ , it was an exciting race.A. compe

By moving the radar beam around slowly in circles, we can ____ the surroundings.

论述一：试结合相关案例论述我国外商独资化的原因。