答案B
分析:byphone(用打电话的方式)(延伸)1)by+不带冠词或物主代词的单数名词表示“交通方式”或“传媒联系方式”,如:bybus,bytrain,bycar,bybike,byplane,byair(=byplane),byship,bysea/byphone,byairmail,byordinarymail,byfastmail,byradio(用无线电联系方式)2)注意onfoot(步行),介词不是by3)Hewenttherebybus.=Hewentthereonabus.=Hetookabustogothere.