Look out! The ceiling l down. A. is to fallB. will fallC. is going to fallD. is falling

网友回答

A. is to fall
B. will fall
(答案→)C. is going to fall
D. is falling
解析：通过“Look out! ”可知房顶将要掉下来，而且是根据某种迹象表明要发生某事，应该使用be going to ，使用答案C。