单选题 Tom: Kate, you are back from vacation! How was it?
Kate: To tell you the truth, I feel tired.
Tom: ______?
Kate: I had to visit all my relatives.
【正确答案】 D
【答案解析】[解析] 本题考查朋友之间的问候。根据上下文，Tom应该是问Kate为什么感觉累，询问原因的固定表达是“How come?”。其他三项不符合语境要求。