【单选题】根据矢量恒等式【图片】,任何一个矢量函数的旋度的 必等于零,可以表示成某一矢量函数的旋度的矢量场称为 场,必然为有位场。
【单选题】RFID(即电子标签)应用的是物联网的( )功能
【简答题】Format means the data ______ in which the electronic record is expressed or to which it refers. Format is used to describe the system language or protocol in which the electronic record is encoded.
【判断题】Feedback refers to any information which provides a report on the result of communication which takes place not only between the listener and the speaker.()
【单选题】RFID(即电子标签)应用的是物联网的( )功能
【简答题】The word“which”refers to__________.
【单选题】( ) refers to a variety of language which is appropriate for a particular situation