单项选择题
Which of the following types of media would MOST likely cause above normal amounts of machine jamming？（）
A.Envelopes B.Colored media C.Letterhead D.Pre punched
单项选择题 Whichofthefollowingitemscanbeusedasadischargelamp？（）
单项选择题 Whichofthefollowingfailedcomponentswouldberesponsibleforthefuserunitnotheatingproperly？（）
单项选择题 Whichofthefollowingdevicescanrouteelectricalsignalsonlywhenactivatedbyanexternalcontrolsignal？（）
