A、13 B、17 C、30 D、15 D女士说“如果Tom和Mary不来参加聚会，我就有13人。”男士说“让我们再多邀请两人以防万一。”该题问“如果每人都来，将有多少人参加这个聚会”。13人加上另外邀请的两人，总共应该是15人。故D项“15”为正确答案。

M: If you had signaled your intention to turn a little sooner, this wouldn’t have happened!
W: But I signaled in time! Just look at the mess you’ve made of my car! You were driving carelessly and your speed was above the limit! You’re the one who’s to blame!
Q: What are they talking about?

W: If Tom and Mary don’t come to the party, I’ll have 13.
M: Let’s invite two more just in case.
Q: If everyone comas, how many will be at the party?