同频干扰是由其它地方发出的不同频率信号所造成的干扰。()
参考答案:错
—I hear Jane has gone to the Holy Island for her holiday.
—Oh, how nice! Do you know when she______________?
A. was leaving
B. had left
C. has left
D. left
企业投资时,首先应对该投资项目进行()
A.可行性分析
B.效益性分析
C.结构性分析
D.方向性分析