【单选题】After he arrived and checked in at the hotel, he filled out a registration___________
【简答题】A.Because he filled out the wrong form. B.Because the officer laughed at him. C.Because he didn't know what form. to get. D.Because he didn't realize the form. was in Spanish.
【简答题】电流通过负载时所做的功叫_______,用____表示。公式是________单位是_______。
【单选题】His eyes ______ tears when he listened to the sad story.
【简答题】在同一种媒体中传输信号时,如果信道长度固定,为了增加传输容量,不可能通过减少 ___________来解决,而只能通过增加_____ 来实现。