试题出自试卷《(全国医学统考)语法阶段模考试题【复制】》

问题1选项
A.You have contacted... we could comply with
B.Had you contacted... we could have complied with
C.You had contacted... could we have complied with
D.Have you contacted... we could comply with

B

考查语法知识。综合题干和选项判断，本题考查的是省略if的虚拟语气。本题表示与过去事实相反的情况，从句用过去完成时，主句用would/could/might/should+现在完成时。因此B选项符合题意。