----Alice why didn’t you come yesterday?--I but I had an unexpected visitor.

问题补充：

------- Alice, why didn’t you come yesterday?

------- I , but I had an unexpected visitor.

A. had

B. would

C. was going to

D. did

答案：

A. had

B. would

(答案→)C. was going to

D. did

解析：考查时态。句意：爱丽丝，昨天你为什么不来？——我打算来了，但是我有一位不速之客。结合语境可知下文描述的是过去计划打算的动作，故用过去将来时态。选C。