微波在大气中传播时由于多径传播引起的衰落称为().
A.绕射衰落
B.波导型衰落
C.干涉衰落
参考答案:C
Shirley Temple (秀兰·邓波儿) became a movie star ________ she was three years old.
[ ]
A. when
B. if
C. because
D. until
尖锐湿疣诊断,在女性应与 __________ 鉴别,在男性应与 __________ 鉴别。