--Can i call you back at two o'clock this afternoon?

问题描述:

--Can i call you back at two o'clock this afternoon?
---i am sorry ,but by then i __ to beijing .How about five?
A fly B will fly C will be flying D am flying
这是陕西2012年高考题

选C,根据意思理解,将来进行时,到那时我正飞往北京了.