---Allen, are you coming with us?-I’d love to, but something unexpected .A. has come up

---Allen, are you coming with us?
---I’d love to, but something unexpected .
A. has come up
B. was coming up
C. had come up
D. would come up

(答案→)A. has come upB. was coming upC. had come upD. would come up解析：come up被提出，出现；come up没有被动形式。根据：你将和我一起去吗？判断这时还未去，没有预料到的事情就已经出现了，come up这个动作与过去没有关系故排除BCD，所以选A。

谢谢了