高三英语he_youaroundourcompanyforhimselfbutforthefactthathewasbusythenhe_youaroundourcompanyforhimselfbutforthefactthathewasbusythen填的是mighthavedone请教一下这里是虚拟用法还是推断用法?

　　高三英语he_youaroundourcompanyforhimselfbutforthefactthathewasbusythen

　　he_youaroundourcompanyforhimselfbutforthefactthathewasbusythen

　　填的是mighthavedone

　　请教一下这里是虚拟用法还是推断用法?