Which of the following is a RF peer to peer mesh protocol used for lighting and other residential electronics？（）

单项选择题WhichofthefollowingisMOSTlikelycausinganintermittentflashingLEDonanIRreceiverwhentheremotecontrolisnotbeingused？（）

A.The power supply is faulty and should be replaced.
B.The heat from a heating， ventilation， and air conditioning （HVAC） register is being received as infrared noise.
C.The radio frequency interference （RFI） is being received as noise.
D.A plasma display is emitting infrared noise.

单项选择题Acustomernotifiestheintegratorthatthesystemkeypadreportstroubleatawindow.Uponinspection，thecustomerfindsthewindowclosedandlocked；thecustomerresetsthesystemanditfailstocorrecttheissue.Whichofthefollowingstepsshouldtheintegratortaketoresolvetheissue？（）

A.Check that the sensor is not misaligned.
B.Clean the space between the sensor and the plate.
C.Toggle the tamper switch to reset the sensor.
D.Bypass the zone.

单项选择题Wheninstallingasecuritysystem，whichofthefollowingconnectorswouldbeusedtoconnectthesecuritysystemtothetelephoneservicedemarcation？（）

A.RJ-31x
B.RJ-11
C.RS-232
D.DB-9

单项选择题Whichofthefollowingdoesanastronomicaltimeclockdo？（）

A.Determines the ambient light at night with a photocell.
B.Calculates sunset and sunrise times based on geographical area.
C.Determines the start and end of each of the seasons.
D.Synchronizes the local time displayed with the official world time.

单项选择题Wiresthatareinstalledinairreturnsaboveaceilingmustbe（）

A.fire proof
B.fiberglass coated
C.plenum rated
D.teflon coated