Which antenna generally has the narrowest first Fresnel zone in both the horizontal and verticalplanes？（）

多项选择题WhichtwomethodscanbeusedtopreventorreduceRFIfromcolocateddirectionalantennas（）

A.Alternate polarization between colocated antennas
B.Cross-polarize antennas between endpoints
C.Install an RF-shielded box around the antennas
D.Increase the distance between the antennas

单项选择题Ciscorecommendsadecibelreferencedto1milliwattsignallevelforthecoveragecelledgeatthepredetermineddataratethatisneededtosupporttheVoWLANdeviceandcallcapacityrequirements.WhatisthatsignallevelvalueforCiscoUnifiedWirelessIPPhones7920，7921G，and7925G？（）

A.-65 dBm
B.-67 dBm
C.-69 dBm
D.-70 dBm

多项选择题WhichthreeformatscanbeusedtoimportfloormapsinCiscoWCSv5.2？（）

A.PNG
B.JPEG
C.GIF
D.BMP
E.PICT
F.TIFF

多项选择题WhichtwoCiscoantennasprovidebetterisolationfromRFsourcesthatmightbelocatedbehindtheantennas？（）

A.AIR-ANT3213
B.AIR-ANT2465P-R
C.AIR-ANT1949
D.AIR-ANT5160V-R

多项选择题WhichthreedevicetypesareidentifiedbyCiscoSpectrumExpertWi-FifindinganAvgPulseDurationparameter？（）

A.Bluetooth
B.frequency hopping
C.microwave oven
D.802.11b client card
E.802.11b access point