When is your birthday?问答 — 英语选择题

Lily想询问Tom的生日，并正确回答自己的生日。阅读对话，选出能补全对话的最佳选项： Lily: Hi, Tom! ________ Tom: My birthday is on October 15th. What about you? Lily: ________ ① When is your birthday?　② When are your birthday?　③ My birthday is on December 1st.　④ My birthday is in December 1st. A. ①③　B. ②③　C. ①④　D. ②④