31 [单选题] He must have had an accident, or he ( ) thenA. would have been hereB. would be hereC. should be hereD. had just had

本题考查虚拟语气在表示与过去事实相反的假设中的用法。关键点在于：

1. 前半句“must have had an accident”是对过去事件的推测，后半句需通过虚拟语气表达与该推测相反的结果；
2. “or”在此处连接的是一个含蓄的条件句，相当于“if he hadn’t had an accident”；
3. 虚拟语气的结构需与过去时间一致，正确形式为“would have + 过去分词”。

选项分析

A. would have been here

• 符合虚拟语气结构：“would have + 过去分词”表示与过去事实相反的假设。
• 逻辑：如果他没有出事故（与“must have had an accident”构成反义），那么“would have been here”表示“本应该出现在这里”。

B. would be here

• 错误原因：使用“would be”表示现在或将来的虚拟，但题目中“then”明确指向过去时间，需用完成时态。

C. should be here

• 错误原因：虽然“should”有推测含义，但“should be”是现在时态，无法体现与过去事实相反的虚拟关系。

D. had just had

• 错误原因：仅用过去完成时描述事实，未体现假设关系，且“had just had”与前文“must have had”重复。