A.天線輻射電磁波經(jīng)墻壁反射后到達(dá)觀察點(diǎn)處對(duì)應(yīng)的電場(chǎng)
B.天線輻射電磁波經(jīng)墻壁和天空反射后到達(dá)觀察點(diǎn)處對(duì)應(yīng)的電場(chǎng)
C.天線直射到觀察點(diǎn)的電磁波對(duì)應(yīng)的電場(chǎng)
D.天線輻射電磁波經(jīng)天空反射后到達(dá)觀察點(diǎn)處對(duì)應(yīng)的電場(chǎng)
A.2
B.4
C.5
D.3
A.2
B.3
C.4
D.5