单选题 ______ before we leave the day after tomorrow, we should have a wonderful time together.
A. Had they arrived B. Would they arrive
C. Were they arriving D. Were they to arrive

【正确答案】 D

【答案解析】[解析] 语法题，考查虚拟语气，虚拟条件句的从句部分如果含有were，should或had，可将if省略，再把were，should或had移到从句句首，实行倒装。此句是混合虚拟，从句中有the day after tomorrow表将来的状语，因此应用were to形式，所以答案是D项。