A.大于0.5 B.0.5 C.不大于0.4 D.小于0.5
A.移頻和UM71 B.移頻和交流計(jì)數(shù) C.交流計(jì)數(shù)和UM71 D.極頻和UM71
A.50 B.小于45 C.不小于45 D.45~55