Each time the distance from the speaker is doubled， volume decreases by（）.

单项选择题AccordingtoOhm’sLaw，whichofthefollowingiscorrect？（）

A.As voltage increases， resistance decreases
B.As amperage decreases， resistance decreases
C.As resistance decreases， amperage increases
D.As resistance increases， voltage increases

单项选择题Whenconfiguringsurroundsoundsystems，speakerdelayisusedtocompensateforspeaker（）.

A.distance
B.power
C.size
D.efficiency

单项选择题WhichofthefollowingBESTdescribesCAT5e？（）

A.Contains four pair of wires of various gauge
B.Contains two wires in a red fireproof jacket
C.Contains four twisted pairs of wires
D.Contains eight wires within a thick jacket with a rip cord

单项选择题RG-6coaxialcableistypicallyusedinallofthefollowingapplications：（）

A.multi-room audio， telephone， intercom and temperature control.
B.thermostat， CCTV， smoke detectors and keypads.
C.home theater， lighting control and multi-room audio.
D.video， digital cable， and satellite applications.

单项选择题Whichofthefollowingcommunicationmethodswillprovidethemaximumbandwidthforvideostreamingthroughamediaextender？（）

A.100BaseT Ethernet
B.802.11g
C.Z-Wave
D.Bluetooth