建立时间和保持时间分析

首先需要理解各个名词含义：

https://blog.csdn.net/Reborn_Lee/article/details/81461955#%E5%BB%BA%E7%AB%8B%E5%92%8C%E4%BF%9D%E6%8C%81%E6%97%B6%E9%97%B4

还有

https://blog.csdn.net/ranggangduo0528/article/details/81112164?ops_request_misc=%257B%2522request%255Fid%2522%253A%2522158622828519724811839215%2522%252C%2522scm%2522%253A%252220140713.130102334..%2522%257D&request_id=158622828519724811839215&biz_id=14&utm_source=distribute.pc_search_result.none-task-blog-soetl_SOETL-4

建立时间和保持时间例题分析：

转载https://blog.csdn.net/Reborn_Lee/article/details/100049997