(室分)3dB电桥的作用()
A.将两路信号合成一路信号
B.把两路或者多路信号合并到单个通路上去
C.实现同频段的多载合路
D.将信源小区信号衰减3dB
参考答案:C
下列选项中,属于计算机病毒特征的是______。
A.多样性
B.传染性
C.随机性
D.免疫性
— He said he would arrive _____ six o’clock. But now it’s nearly seven.
— Maybe he will arrive _____ a few minutes.
A.at; in
B.in; in
C.after; after
D.in; after