答案：B

题目分析：考虚拟条件句的省略倒装句：句意：如果我知道你今天要来这儿，我就会到火车站去接你了。这是一个虚拟条件句，正常的表达是：if I had known you were coming today, I’d have met you at the railway station.在虚拟语气里面，如果有if就用正常的语序，省略if是要把had，were，should提前，选B。

点评：if的虚拟语气非常重要，简要概括如下：1、表示与现 在事实相反的情况，从句：If主语+过去时(Be动词用were)；主句：主语+should/would/could/might+do：　2、表示与过去事实相反的情况，从句：If主语+had+done；主句：主语+should/ would/ could/ might+have done　3、表示对将来情况的主观推测，从句：①if+主语+were to do②if+主语+should+do ③if+主语+did（动词过去式）/were ；主句：主语+should /would/ could /might+do，从句也可以省略if，把had，were，should提前。