7、ulartruckintheworld答案 C [细节理解题。根据文章第二段Thesystemsendsvideofootageinfrontofatrucktofourscreensonitsback.Itgivesdriversaclearviewofwhat'sahead.“Webelievethiswillchangethehistoryofroadsafety,”可知,安全卡车能告诉司机前方有什么,可以极大地减少交通事故。]2.WhatmakestheApplePencildifferentfromthemonpen