下列哪种情况是由于手机和基站间的障碍物引起的()。
A.瑞利衰落(Rayleighfading)
B.路径衰耗(Pathloss)
C.阴影效应(Shadowing)
参考答案:C
Computers are used workers helping make many dinfferent things now.
A.to, for
B.by, for
C.by, to
D.for, to
人免疫缺陷病毒属于()
A.单链DNA病毒
B.双链DNA病毒
C.单链RNA病毒
D.双链RNA病毒
E.缺陷型病毒