单项选择题
Small in-ceiling speakers are BEST suited for（）
A.loud， bass intensive music （e.g. heavy metal， rock）. B.providing a sub-woofer for great bass reproduction. C.background music and blending in with decor. D.the user who wants perfect sound reproduction.
单项选择题 WhichofthefollowingisthecorrectwiringorderforanRJ-11twolinejack？（）
单项选择题 Whichofthefollowingdeterminesifthealarmshouldsoundoranentrydelayshouldstart？（）
单项选择题 WhichofthefollowingisaRFpeertopeermeshprotocolusedforlightingandotherresidentialelectronics？（）
