虚拟结构中的条件状语从句省略 if 后， were , had 和 should 应该移到主语之前。例如：If you had worked harder at college, You would have got a better job. = Had you worked harder at college, You would have got a better job.如果你在大学期间读书用功些，就会找到一份更好的工作了。

    所以，Had we done so, each of us would have had about 50% heads. = If we had done so, each of us would have had about 50% heads.