题目

如图，下列条件中能判断直线l1//l2的是    (    )     A．∠1＝∠2     B．∠1＝∠5    C．∠1＋∠3＝180°  D．∠3＝∠5 答案：C —Where is Mr. White?—Oh， he hasn’t come yet. He is supposed to _____ in an hour. A. arriving B. arrive C. arrived D. arrives