My sister will get up early tomorrow morning，because the train to London at 6:00 a.m.
A. will leave
B. is going to leave
C. is to leave
D. leaves
网友回答
A. will leave
B. is going to leave
C. is to leave
(答案→)D. leaves
解析：
试题分析:考查动词时态。四个选项均表示将来，但是will +v原形表示一时决定的；be going to do 和be to do表示按计划打算要做的；而D选项一般现在时可以表示按列车或航班时间表规定的出发或到达，由此可知D选项正确。句意：我姐姐明天要早起，因为通往伦敦的列车上午六点就出发。