单项选择题
Which of the following is a diplexer used for？（）
A.Allows two satellite tuners to use the same dish. B.Connects the low noise block down converter （LNB） to the multi-switch. C.Combines satellite and over the air （OTA） signals. D.Allows one LNB to use two satellites.
单项选择题 Whichofthefollowingistheprimarypurposeofimpedancematchedvolumecontrol？（）
单项选择题 Thenativeresolutionfor1080iis（）
单项选择题 Eachtimethedistancefromthespeakerisdoubled，volumedecreasesby（）.
