单选题 ______you cannot pick me up at the airport, please call me immediately.
A. In order that B. In the event that C. If only D. Unless

【正确答案】 B

【答案解析】[解析] 句子大意为：如果你不能到机场接我，请立即给我打电话。本题考查常用表达辨析。在给出的选项中：in order that“为了”；in the event that“如果”；if only“只要”；unless “除非”。所以，正确答案是B。