__________ I you, I would go with him to the party.A. WasB. Had beenC. Will beD. Were

本题考查虚拟语气的用法，特别是省略if的虚拟条件句的结构。关键点在于：

1. 虚拟条件句中，当从句省略if时，需将助动词were, had, should提前，实现主谓倒装；
2. 主句中的would go表明这是对现在事实的虚拟假设，因此从句应使用were（而非was）。

句子结构分析

原句为省略if的虚拟条件句，完整形式应为：
If I were you, I would go with him to the party.
省略if后，需将were提前并倒装主谓：
Were I you, I would go with him to the party.

选项辨析

• A. Was：过去式，不符合虚拟语气中对现在事实的假设（需用were）；
• B. Had been：表示对过去的虚拟，但主句用would go（对现在动作的虚拟）；
• C. Will be：表示将来，与虚拟语气的假设性质矛盾；
• D. Were：正确形式，符合省略if的虚拟条件句结构。