你应该用虚拟语气
、表示对将来情况的主观推测
从句：①if+主语+were to do 主句：①主语+should/would/could/might+do
　②if+主语+did/were ②主语+should/would/could/might+do　
　③if+主语+should+do ③主语+should/would/could/might+do　
If tomorrow were to be the last day of your life ,what would you do?